Re: [DISCUSS] Custom Control Tuples Design

[Amol Kekre]

This is needed, the batch start-end have similar semantics as start-end
window from operational/functional perspective.

Thks
Amol


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On Tue, Feb 14, 2017 at 9:55 PM, Bhupesh Chawda 
wrote:

> +1 for having an immediate delivery mechanism as well.
>
> I would suggest that the other delivery mechanism stays at end of window,
> to be consistent, as I think it may be difficult to determine the last
> arrival of the tuple.
>
> ~ Bhupesh
>
> On Wed, Feb 15, 2017 at 7:04 AM, Pramod Immaneni 
> wrote:
>
> > There have been some recent developments and discussions on the schema
> side
> > (link below) that warrant a reconsideration of how control tuples get
> > delivered.
> >
> > http://apache.markmail.org/search/?q=apex+list%3Aorg.
> > apache.apex.dev+schema+discovery+support#query:apex%
> > 20list%3Aorg.apache.apex.dev%20schema%20discovery%20support+page:1+mid:
> > oaji26y3xfozap5v+state:results
> >
> > What I would like to suggest is that we allow two delivery options for
> > control tuples which can be configured on a per control tuple basis.
> First
> > is to deliver control tuple to the operator when the first instance of
> the
> > tuple arrives from any path. Second option is to deliver the control
> tuple
> > when the last instance of the tuple arrives from all the paths or at the
> > end window if it is going to be difficult to determine the last arrival.
> > The developer can choose the delivery option for the control tuple
> > preferably when the tuple is created. The first option will be useful for
> > scenarios like schema propagation or begin file in case of batch cases.
> The
> > second option will be useful for tuples like end file or end batch in
> batch
> > use cases.
> >
> > Thanks
> >
> > On Tue, Jan 10, 2017 at 12:27 PM, Bhupesh Chawda <
> bhup...@datatorrent.com>
> > wrote:
> >
> > > Hi All,
> > >
> > > Based on some discussion here is what is planned for the propagation
> > > feature for control tuples.
> > >
> > > The signature of the *processControl()* method in
> > > *ControlAwareDefaultInputPort* which is implemented by the operator
> > > developer will be as follows:
> > >
> > > *public abstract boolean processControl(UserDefinedControlTuple
> > payload);*
> > >
> > > The boolean returned by the processControl() method indicates (to the
> > > engine) whether or not the operator is able to handle the control tuple
> > and
> > > wants to take care of the propagation of the control tuple.
> > >
> > >- If the method returns true - indicating it is able to handle the
> > >control tuple, the operator has to explicitly emit the control
> tuples
> > to
> > >the output ports it wishes to propagate to.
> > >
> > >
> > >- If the method returns false - indicating it is not able to handle
> > the
> > >control tuple, the control tuple will be propagated by the engine to
> > all
> > >output ports.
> > >
> > > The operator may even emit new control tuples in either of the cases.
> > > Note that for ports that are not control aware, the control tuple is
> > > propagated by default.
> > >
> > > We don't need any output port annotations or operator level attributes.
> > >
> > > ~ Bhupesh
> > >
> > >
> > > On Mon, Jan 9, 2017 at 5:16 PM, Tushar Gosavi 
> > > wrote:
> > >
> > > > On Sun, Jan 8, 2017 at 11:49 PM, Vlad Rozov  >
> > > > wrote:
> > > > > +1 to manage propagation at an operator level. An operator is
> either
> > > > control
> > > > > tuple aware and needs to manage how control tuples are routed from
> > > input
> > > > > ports to output ports or it is not. In the later case it does not
> > > matter
> > > > how
> > > > > many input and output ports the operator has and it is the Apex
> > > platform
> > > > > responsibility to route control tuples. I don't see a use case
> where
> > an
> > > > > operator that is not aware of a control tuple needs to manage one
> or
> > > more
> > > > > input ports (or similar output ports) differently than others.
> > > > >
> > > >
> > > > The problem with giving explicit control to operator for routing of
> > > > custom tuples is how does the operator
> > > > developer knows about control tuple requirement for downstream
> > > > operators in an application. For example in following DAG
> > > > A -> B -> C
> > > > A - is my custom source operator which emits a new control tuple type
> > C1
> > > > and C.
> > > > B - is operator from malhar which handle control tuple C.
> > > > C - is custom output operator which handles C1.
> > > >
> > > > If B is managing control tuples, then it needs to remember to foward
> > > > unhandled tuples on all output port, else it will block
> > > > the tuples for downstream operator which might need them, 

Re: [DISCUSS] Custom Control Tuples Design

[Bhupesh Chawda]

+1 for having an immediate delivery mechanism as well.

I would suggest that the other delivery mechanism stays at end of window,
to be consistent, as I think it may be difficult to determine the last
arrival of the tuple.

~ Bhupesh

On Wed, Feb 15, 2017 at 7:04 AM, Pramod Immaneni 
wrote:

> There have been some recent developments and discussions on the schema side
> (link below) that warrant a reconsideration of how control tuples get
> delivered.
>
> http://apache.markmail.org/search/?q=apex+list%3Aorg.
> apache.apex.dev+schema+discovery+support#query:apex%
> 20list%3Aorg.apache.apex.dev%20schema%20discovery%20support+page:1+mid:
> oaji26y3xfozap5v+state:results
>
> What I would like to suggest is that we allow two delivery options for
> control tuples which can be configured on a per control tuple basis. First
> is to deliver control tuple to the operator when the first instance of the
> tuple arrives from any path. Second option is to deliver the control tuple
> when the last instance of the tuple arrives from all the paths or at the
> end window if it is going to be difficult to determine the last arrival.
> The developer can choose the delivery option for the control tuple
> preferably when the tuple is created. The first option will be useful for
> scenarios like schema propagation or begin file in case of batch cases. The
> second option will be useful for tuples like end file or end batch in batch
> use cases.
>
> Thanks
>
> On Tue, Jan 10, 2017 at 12:27 PM, Bhupesh Chawda 
> wrote:
>
> > Hi All,
> >
> > Based on some discussion here is what is planned for the propagation
> > feature for control tuples.
> >
> > The signature of the *processControl()* method in
> > *ControlAwareDefaultInputPort* which is implemented by the operator
> > developer will be as follows:
> >
> > *public abstract boolean processControl(UserDefinedControlTuple
> payload);*
> >
> > The boolean returned by the processControl() method indicates (to the
> > engine) whether or not the operator is able to handle the control tuple
> and
> > wants to take care of the propagation of the control tuple.
> >
> >- If the method returns true - indicating it is able to handle the
> >control tuple, the operator has to explicitly emit the control tuples
> to
> >the output ports it wishes to propagate to.
> >
> >
> >- If the method returns false - indicating it is not able to handle
> the
> >control tuple, the control tuple will be propagated by the engine to
> all
> >output ports.
> >
> > The operator may even emit new control tuples in either of the cases.
> > Note that for ports that are not control aware, the control tuple is
> > propagated by default.
> >
> > We don't need any output port annotations or operator level attributes.
> >
> > ~ Bhupesh
> >
> >
> > On Mon, Jan 9, 2017 at 5:16 PM, Tushar Gosavi 
> > wrote:
> >
> > > On Sun, Jan 8, 2017 at 11:49 PM, Vlad Rozov 
> > > wrote:
> > > > +1 to manage propagation at an operator level. An operator is either
> > > control
> > > > tuple aware and needs to manage how control tuples are routed from
> > input
> > > > ports to output ports or it is not. In the later case it does not
> > matter
> > > how
> > > > many input and output ports the operator has and it is the Apex
> > platform
> > > > responsibility to route control tuples. I don't see a use case where
> an
> > > > operator that is not aware of a control tuple needs to manage one or
> > more
> > > > input ports (or similar output ports) differently than others.
> > > >
> > >
> > > The problem with giving explicit control to operator for routing of
> > > custom tuples is how does the operator
> > > developer knows about control tuple requirement for downstream
> > > operators in an application. For example in following DAG
> > > A -> B -> C
> > > A - is my custom source operator which emits a new control tuple type
> C1
> > > and C.
> > > B - is operator from malhar which handle control tuple C.
> > > C - is custom output operator which handles C1.
> > >
> > > If B is managing control tuples, then it needs to remember to foward
> > > unhandled tuples on all output port, else it will block
> > > the tuples for downstream operator which might need them, also if new
> > > output port is added then B needs to send that tuples
> > > on the new output port also. But In this case I can't simply extend B
> > > as port objects are transient and mostly anonymous,
> > > I can not extend these to send control tuples on new output port. In
> > > my opinion we should let the control tuple flow through
> > > entire DAG from their source and let each operator in the path to
> > > handle/ignore them as required without blocking them.
> > >
> > >
> > > > In general, an operator is aware only of a specific control tuple(s)
> > (for
> > > > example end of batch or end of file) and for a control tuples that it
> > was
> > > > 

Re: [DISCUSS] Custom Control Tuples Design

[Pramod Immaneni]

There have been some recent developments and discussions on the schema side
(link below) that warrant a reconsideration of how control tuples get
delivered.

http://apache.markmail.org/search/?q=apex+list%3Aorg.apache.apex.dev+schema+discovery+support#query:apex%20list%3Aorg.apache.apex.dev%20schema%20discovery%20support+page:1+mid:oaji26y3xfozap5v+state:results

What I would like to suggest is that we allow two delivery options for
control tuples which can be configured on a per control tuple basis. First
is to deliver control tuple to the operator when the first instance of the
tuple arrives from any path. Second option is to deliver the control tuple
when the last instance of the tuple arrives from all the paths or at the
end window if it is going to be difficult to determine the last arrival.
The developer can choose the delivery option for the control tuple
preferably when the tuple is created. The first option will be useful for
scenarios like schema propagation or begin file in case of batch cases. The
second option will be useful for tuples like end file or end batch in batch
use cases.

Thanks

On Tue, Jan 10, 2017 at 12:27 PM, Bhupesh Chawda 
wrote:

> Hi All,
>
> Based on some discussion here is what is planned for the propagation
> feature for control tuples.
>
> The signature of the *processControl()* method in
> *ControlAwareDefaultInputPort* which is implemented by the operator
> developer will be as follows:
>
> *public abstract boolean processControl(UserDefinedControlTuple payload);*
>
> The boolean returned by the processControl() method indicates (to the
> engine) whether or not the operator is able to handle the control tuple and
> wants to take care of the propagation of the control tuple.
>
>- If the method returns true - indicating it is able to handle the
>control tuple, the operator has to explicitly emit the control tuples to
>the output ports it wishes to propagate to.
>
>
>- If the method returns false - indicating it is not able to handle the
>control tuple, the control tuple will be propagated by the engine to all
>output ports.
>
> The operator may even emit new control tuples in either of the cases.
> Note that for ports that are not control aware, the control tuple is
> propagated by default.
>
> We don't need any output port annotations or operator level attributes.
>
> ~ Bhupesh
>
>
> On Mon, Jan 9, 2017 at 5:16 PM, Tushar Gosavi 
> wrote:
>
> > On Sun, Jan 8, 2017 at 11:49 PM, Vlad Rozov 
> > wrote:
> > > +1 to manage propagation at an operator level. An operator is either
> > control
> > > tuple aware and needs to manage how control tuples are routed from
> input
> > > ports to output ports or it is not. In the later case it does not
> matter
> > how
> > > many input and output ports the operator has and it is the Apex
> platform
> > > responsibility to route control tuples. I don't see a use case where an
> > > operator that is not aware of a control tuple needs to manage one or
> more
> > > input ports (or similar output ports) differently than others.
> > >
> >
> > The problem with giving explicit control to operator for routing of
> > custom tuples is how does the operator
> > developer knows about control tuple requirement for downstream
> > operators in an application. For example in following DAG
> > A -> B -> C
> > A - is my custom source operator which emits a new control tuple type C1
> > and C.
> > B - is operator from malhar which handle control tuple C.
> > C - is custom output operator which handles C1.
> >
> > If B is managing control tuples, then it needs to remember to foward
> > unhandled tuples on all output port, else it will block
> > the tuples for downstream operator which might need them, also if new
> > output port is added then B needs to send that tuples
> > on the new output port also. But In this case I can't simply extend B
> > as port objects are transient and mostly anonymous,
> > I can not extend these to send control tuples on new output port. In
> > my opinion we should let the control tuple flow through
> > entire DAG from their source and let each operator in the path to
> > handle/ignore them as required without blocking them.
> >
> >
> > > In general, an operator is aware only of a specific control tuple(s)
> (for
> > > example end of batch or end of file) and for a control tuples that it
> was
> > > not enabled for, the behavior should be exactly the same as if the
> > operator
> > > is not control tuple aware, meaning that those control tuples should be
> > > propagated from input ports to output ports by the platform. There
> > should be
> > > an ability to let the platform know what control tuples an operator is
> > aware
> > > of and can handle. This can be done both by API call and an annotation.
> > >
> >
> > I think this will add overhead while developing applications. Operator
> > developer needs to add code to handle new 

Re: [DISCUSS] Custom Control Tuples Design

[Bhupesh Chawda]

Hi All,

Based on some discussion here is what is planned for the propagation
feature for control tuples.

The signature of the *processControl()* method in
*ControlAwareDefaultInputPort* which is implemented by the operator
developer will be as follows:

*public abstract boolean processControl(UserDefinedControlTuple payload);*

The boolean returned by the processControl() method indicates (to the
engine) whether or not the operator is able to handle the control tuple and
wants to take care of the propagation of the control tuple.

   - If the method returns true - indicating it is able to handle the
   control tuple, the operator has to explicitly emit the control tuples to
   the output ports it wishes to propagate to.


   - If the method returns false - indicating it is not able to handle the
   control tuple, the control tuple will be propagated by the engine to all
   output ports.

The operator may even emit new control tuples in either of the cases.
Note that for ports that are not control aware, the control tuple is
propagated by default.

We don't need any output port annotations or operator level attributes.

~ Bhupesh


On Mon, Jan 9, 2017 at 5:16 PM, Tushar Gosavi 
wrote:

> On Sun, Jan 8, 2017 at 11:49 PM, Vlad Rozov 
> wrote:
> > +1 to manage propagation at an operator level. An operator is either
> control
> > tuple aware and needs to manage how control tuples are routed from input
> > ports to output ports or it is not. In the later case it does not matter
> how
> > many input and output ports the operator has and it is the Apex platform
> > responsibility to route control tuples. I don't see a use case where an
> > operator that is not aware of a control tuple needs to manage one or more
> > input ports (or similar output ports) differently than others.
> >
>
> The problem with giving explicit control to operator for routing of
> custom tuples is how does the operator
> developer knows about control tuple requirement for downstream
> operators in an application. For example in following DAG
> A -> B -> C
> A - is my custom source operator which emits a new control tuple type C1
> and C.
> B - is operator from malhar which handle control tuple C.
> C - is custom output operator which handles C1.
>
> If B is managing control tuples, then it needs to remember to foward
> unhandled tuples on all output port, else it will block
> the tuples for downstream operator which might need them, also if new
> output port is added then B needs to send that tuples
> on the new output port also. But In this case I can't simply extend B
> as port objects are transient and mostly anonymous,
> I can not extend these to send control tuples on new output port. In
> my opinion we should let the control tuple flow through
> entire DAG from their source and let each operator in the path to
> handle/ignore them as required without blocking them.
>
>
> > In general, an operator is aware only of a specific control tuple(s) (for
> > example end of batch or end of file) and for a control tuples that it was
> > not enabled for, the behavior should be exactly the same as if the
> operator
> > is not control tuple aware, meaning that those control tuples should be
> > propagated from input ports to output ports by the platform. There
> should be
> > an ability to let the platform know what control tuples an operator is
> aware
> > of and can handle. This can be done both by API call and an annotation.
> >
>
> I think this will add overhead while developing applications. Operator
> developer needs to add code to handle new control tuple also
> need to update the part of code to register the type with engine. And
> platfoms needs to perform type check and develiver the tuples
> accordingly. Instead operator developer could check the type of
> incoming tuple and handle it as required.
>
> - Tushar.
>
>
> > Thank you,
> >
> > Vlad
> >
> >
> > On 1/5/17 13:04, Bhupesh Chawda wrote:
> >>
> >> Agreed Thomas.
> >> I was referring to the persona of the operator developer. The user of
> the
> >> operator would not be doing anything related to the propagation of
> control
> >> tuples. Actually, the behavior of the operator wrt. propagation of
> control
> >> tuples would be part of the operator documentation.
> >>
> >> Also, we are providing options for the developer to route the flow of
> >> control tuples in code during the development of the operator. The
> >> annotations would actually help achieve it in a easier way.
> >>
> >> ~ Bhupesh
> >>
> >> On Jan 5, 2017 21:40, "Thomas Weise"  wrote:
> >>
> >> I think it is important to be clear on the roles with regard to this
> >> functionality. The user of the operator should not have to do anything
> to
> >> get it to work. So while I suggested to consider attributes earlier,
> there
> >> should not be any need for the user to set those. The operator needs to
> >> work as is.
> >>
> >> The persona concerned with 

Re: [DISCUSS] Custom Control Tuples Design

[Tushar Gosavi]

On Sun, Jan 8, 2017 at 11:49 PM, Vlad Rozov  wrote:
> +1 to manage propagation at an operator level. An operator is either control
> tuple aware and needs to manage how control tuples are routed from input
> ports to output ports or it is not. In the later case it does not matter how
> many input and output ports the operator has and it is the Apex platform
> responsibility to route control tuples. I don't see a use case where an
> operator that is not aware of a control tuple needs to manage one or more
> input ports (or similar output ports) differently than others.
>

The problem with giving explicit control to operator for routing of
custom tuples is how does the operator
developer knows about control tuple requirement for downstream
operators in an application. For example in following DAG
A -> B -> C
A - is my custom source operator which emits a new control tuple type C1 and C.
B - is operator from malhar which handle control tuple C.
C - is custom output operator which handles C1.

If B is managing control tuples, then it needs to remember to foward
unhandled tuples on all output port, else it will block
the tuples for downstream operator which might need them, also if new
output port is added then B needs to send that tuples
on the new output port also. But In this case I can't simply extend B
as port objects are transient and mostly anonymous,
I can not extend these to send control tuples on new output port. In
my opinion we should let the control tuple flow through
entire DAG from their source and let each operator in the path to
handle/ignore them as required without blocking them.


> In general, an operator is aware only of a specific control tuple(s) (for
> example end of batch or end of file) and for a control tuples that it was
> not enabled for, the behavior should be exactly the same as if the operator
> is not control tuple aware, meaning that those control tuples should be
> propagated from input ports to output ports by the platform. There should be
> an ability to let the platform know what control tuples an operator is aware
> of and can handle. This can be done both by API call and an annotation.
>

I think this will add overhead while developing applications. Operator
developer needs to add code to handle new control tuple also
need to update the part of code to register the type with engine. And
platfoms needs to perform type check and develiver the tuples
accordingly. Instead operator developer could check the type of
incoming tuple and handle it as required.

- Tushar.


> Thank you,
>
> Vlad
>
>
> On 1/5/17 13:04, Bhupesh Chawda wrote:
>>
>> Agreed Thomas.
>> I was referring to the persona of the operator developer. The user of the
>> operator would not be doing anything related to the propagation of control
>> tuples. Actually, the behavior of the operator wrt. propagation of control
>> tuples would be part of the operator documentation.
>>
>> Also, we are providing options for the developer to route the flow of
>> control tuples in code during the development of the operator. The
>> annotations would actually help achieve it in a easier way.
>>
>> ~ Bhupesh
>>
>> On Jan 5, 2017 21:40, "Thomas Weise"  wrote:
>>
>> I think it is important to be clear on the roles with regard to this
>> functionality. The user of the operator should not have to do anything to
>> get it to work. So while I suggested to consider attributes earlier, there
>> should not be any need for the user to set those. The operator needs to
>> work as is.
>>
>> The persona concerned with propagation of control tuples is the operator
>> developer. I think the clear way for the operator developer to override
>> the
>> propagation behavior is in code and if that is possible there is no need
>> for other things such as attributes or other port level settings.
>>
>> Thomas
>>
>>
>> On Wed, Jan 4, 2017 at 10:20 PM, Bhupesh Chawda 
>> wrote:
>>
>>> I think we all agree on the use case for selective propagation. The
>>> question is about where to have the control - at the operator level or at
>>> the port level.
>>>
>>> For this ability, we have the following options:
>>>
>>> 1. Operator disables the propagation on selected output ports. Other
>>> output ports propagate by default.
>>> 2. Operator disables propagation for the entire operator (by means of
>>
>> an
>>>
>>> attribute). Operator developer explicitly emits the received control
>>> tuples
>>> on selected output ports.
>>>
>>> If the decision is to completely block the propagation, then Option 2 is
>>> easier to use as just an attribute needs to be set, as opposed to Option
>>> 1
>>> where user needs to set the annotation on each output port.
>>>
>>> However, if selective propagation is needed, Option 1 would just need the
>>> user to disable propagation on certain ports; rest are propagated by
>>> default, while Option 2 requires the user to explicitly emit the control

Re: [DISCUSS] Custom Control Tuples Design

[Bhupesh Chawda]

Hi All,

Whether the operator is control tuple aware can be determined by the type
of ports it uses; specifically the Input Port. I think this should be a
sufficient condition to infer the control tuple awareness of the operator.
Any cases where this assumption may not hold?

Are you suggesting that because an operator can consume a control tuple
(since it has a control tuple aware input port), that the engine should
leave the responsibility of propagation to the user?
Note that if this is the case, and if the user forgets to explicitly emit
the control tuples to the output port, the downstream operator would not
get them.
I don't think there should be a correlation between whether an operator is
control tuple aware and whether the operator allows propagation. An
operator may be Control Tuple aware and may choose independently, whether
or not to allow propagation and still emit new control tuples all at the
same time.

~ Bhupesh


On Sun, Jan 8, 2017 at 11:49 PM, Vlad Rozov  wrote:

> +1 to manage propagation at an operator level. An operator is either
> control tuple aware and needs to manage how control tuples are routed from
> input ports to output ports or it is not. In the later case it does not
> matter how many input and output ports the operator has and it is the Apex
> platform responsibility to route control tuples. I don't see a use case
> where an operator that is not aware of a control tuple needs to manage one
> or more input ports (or similar output ports) differently than others.
>
> In general, an operator is aware only of a specific control tuple(s) (for
> example end of batch or end of file) and for a control tuples that it was
> not enabled for, the behavior should be exactly the same as if the operator
> is not control tuple aware, meaning that those control tuples should be
> propagated from input ports to output ports by the platform. There should
> be an ability to let the platform know what control tuples an operator is
> aware of and can handle. This can be done both by API call and an
> annotation.
>
> Thank you,
>
> Vlad
>
>
> On 1/5/17 13:04, Bhupesh Chawda wrote:
>
>> Agreed Thomas.
>> I was referring to the persona of the operator developer. The user of the
>> operator would not be doing anything related to the propagation of control
>> tuples. Actually, the behavior of the operator wrt. propagation of control
>> tuples would be part of the operator documentation.
>>
>> Also, we are providing options for the developer to route the flow of
>> control tuples in code during the development of the operator. The
>> annotations would actually help achieve it in a easier way.
>>
>> ~ Bhupesh
>>
>> On Jan 5, 2017 21:40, "Thomas Weise"  wrote:
>>
>> I think it is important to be clear on the roles with regard to this
>> functionality. The user of the operator should not have to do anything to
>> get it to work. So while I suggested to consider attributes earlier, there
>> should not be any need for the user to set those. The operator needs to
>> work as is.
>>
>> The persona concerned with propagation of control tuples is the operator
>> developer. I think the clear way for the operator developer to override
>> the
>> propagation behavior is in code and if that is possible there is no need
>> for other things such as attributes or other port level settings.
>>
>> Thomas
>>
>>
>> On Wed, Jan 4, 2017 at 10:20 PM, Bhupesh Chawda 
>> wrote:
>>
>> I think we all agree on the use case for selective propagation. The
>>> question is about where to have the control - at the operator level or at
>>> the port level.
>>>
>>> For this ability, we have the following options:
>>>
>>> 1. Operator disables the propagation on selected output ports. Other
>>> output ports propagate by default.
>>> 2. Operator disables propagation for the entire operator (by means of
>>>
>> an
>>
>>> attribute). Operator developer explicitly emits the received control
>>> tuples
>>> on selected output ports.
>>>
>>> If the decision is to completely block the propagation, then Option 2 is
>>> easier to use as just an attribute needs to be set, as opposed to Option
>>> 1
>>> where user needs to set the annotation on each output port.
>>>
>>> However, if selective propagation is needed, Option 1 would just need the
>>> user to disable propagation on certain ports; rest are propagated by
>>> default, while Option 2 requires the user to explicitly emit the control
>>> tuples.
>>> ~ Bhupesh
>>>
>>>
>>> On Thu, Jan 5, 2017 at 3:46 AM, Thomas Weise  wrote:
>>>
>>> Yes, I think that for any of these cases the operator developer will

>>> turn
>>
>>> of implicit propagation for the operator and then write the code to

>>> route
>>
>>> or create control tuples as needed.

 Thomas

 On Wed, Jan 4, 2017 at 12:59 PM, Amol Kekre 

>>> wrote:
>>>
 I agree that by default the 

Re: [DISCUSS] Custom Control Tuples Design

[Vlad Rozov]

+1 to manage propagation at an operator level. An operator is either 
control tuple aware and needs to manage how control tuples are routed 
from input ports to output ports or it is not. In the later case it does 
not matter how many input and output ports the operator has and it is 
the Apex platform responsibility to route control tuples. I don't see a 
use case where an operator that is not aware of a control tuple needs to 
manage one or more input ports (or similar output ports) differently 
than others.


In general, an operator is aware only of a specific control tuple(s) 
(for example end of batch or end of file) and for a control tuples that 
it was not enabled for, the behavior should be exactly the same as if 
the operator is not control tuple aware, meaning that those control 
tuples should be propagated from input ports to output ports by the 
platform. There should be an ability to let the platform know what 
control tuples an operator is aware of and can handle. This can be done 
both by API call and an annotation.


Thank you,

Vlad


On 1/5/17 13:04, Bhupesh Chawda wrote:

Agreed Thomas.
I was referring to the persona of the operator developer. The user of the
operator would not be doing anything related to the propagation of control
tuples. Actually, the behavior of the operator wrt. propagation of control
tuples would be part of the operator documentation.

Also, we are providing options for the developer to route the flow of
control tuples in code during the development of the operator. The
annotations would actually help achieve it in a easier way.

~ Bhupesh

On Jan 5, 2017 21:40, "Thomas Weise"  wrote:

I think it is important to be clear on the roles with regard to this
functionality. The user of the operator should not have to do anything to
get it to work. So while I suggested to consider attributes earlier, there
should not be any need for the user to set those. The operator needs to
work as is.

The persona concerned with propagation of control tuples is the operator
developer. I think the clear way for the operator developer to override the
propagation behavior is in code and if that is possible there is no need
for other things such as attributes or other port level settings.

Thomas


On Wed, Jan 4, 2017 at 10:20 PM, Bhupesh Chawda 
wrote:


I think we all agree on the use case for selective propagation. The
question is about where to have the control - at the operator level or at
the port level.

For this ability, we have the following options:

1. Operator disables the propagation on selected output ports. Other
output ports propagate by default.
2. Operator disables propagation for the entire operator (by means of

an

attribute). Operator developer explicitly emits the received control
tuples
on selected output ports.

If the decision is to completely block the propagation, then Option 2 is
easier to use as just an attribute needs to be set, as opposed to Option 1
where user needs to set the annotation on each output port.

However, if selective propagation is needed, Option 1 would just need the
user to disable propagation on certain ports; rest are propagated by
default, while Option 2 requires the user to explicitly emit the control
tuples.
~ Bhupesh


On Thu, Jan 5, 2017 at 3:46 AM, Thomas Weise  wrote:


Yes, I think that for any of these cases the operator developer will

turn

of implicit propagation for the operator and then write the code to

route

or create control tuples as needed.

Thomas

On Wed, Jan 4, 2017 at 12:59 PM, Amol Kekre 

wrote:

I agree that by default the propagation must be implicit, i.e. if the
operator does nothing, the control tuple propagates. I do think users
should have control on deciding to "not propagate" or "create new" and

in

these cases they would need to do something explicit (override)?

The following cases come to mind
1. Sole consumer of a particular control signal (for example end of

file)

2. Creator of a particular control signal (start of file, or a signal

to

pause on something etc.)
3. One port on a data pipeline and other port for meta-data pipeline

In the above cases emit will be decided on an output port. #1 is only

place

where all output ports will disable the tuple, #2 and #3 most likely

will

be selective.

Thks
Amol


On Wed, Jan 4, 2017 at 12:25 PM, Thomas Weise  wrote:


I think there is (1) implicit propagation just like other control

tuples

where the operator code isn't involved and (2) where the operator

developer

wants to decide how control tuples are created or routed and will

receive

and emit them on the output ports as desired.

I don't see a use case for hybrid approaches? Maybe propagation does

not

need to be tied to ports at all, maybe just by annotation at the

operator

level?

Thomas


On Wed, Jan 4, 2017 at 10:59 AM, Bhupesh Chawda <

bhup...@datatorrent.com

wrote:

Re: [DISCUSS] Custom Control Tuples Design

[Bhupesh Chawda]

Agreed Thomas.
I was referring to the persona of the operator developer. The user of the
operator would not be doing anything related to the propagation of control
tuples. Actually, the behavior of the operator wrt. propagation of control
tuples would be part of the operator documentation.

Also, we are providing options for the developer to route the flow of
control tuples in code during the development of the operator. The
annotations would actually help achieve it in a easier way.

~ Bhupesh

On Jan 5, 2017 21:40, "Thomas Weise"  wrote:

I think it is important to be clear on the roles with regard to this
functionality. The user of the operator should not have to do anything to
get it to work. So while I suggested to consider attributes earlier, there
should not be any need for the user to set those. The operator needs to
work as is.

The persona concerned with propagation of control tuples is the operator
developer. I think the clear way for the operator developer to override the
propagation behavior is in code and if that is possible there is no need
for other things such as attributes or other port level settings.

Thomas


On Wed, Jan 4, 2017 at 10:20 PM, Bhupesh Chawda 
wrote:

> I think we all agree on the use case for selective propagation. The
> question is about where to have the control - at the operator level or at
> the port level.
>
> For this ability, we have the following options:
>
>1. Operator disables the propagation on selected output ports. Other
>output ports propagate by default.
>2. Operator disables propagation for the entire operator (by means of
an
>attribute). Operator developer explicitly emits the received control
> tuples
>on selected output ports.
>
> If the decision is to completely block the propagation, then Option 2 is
> easier to use as just an attribute needs to be set, as opposed to Option 1
> where user needs to set the annotation on each output port.
>
> However, if selective propagation is needed, Option 1 would just need the
> user to disable propagation on certain ports; rest are propagated by
> default, while Option 2 requires the user to explicitly emit the control
> tuples.
> ~ Bhupesh
>
>
> On Thu, Jan 5, 2017 at 3:46 AM, Thomas Weise  wrote:
>
> > Yes, I think that for any of these cases the operator developer will
turn
> > of implicit propagation for the operator and then write the code to
route
> > or create control tuples as needed.
> >
> > Thomas
> >
> > On Wed, Jan 4, 2017 at 12:59 PM, Amol Kekre 
> wrote:
> >
> > > I agree that by default the propagation must be implicit, i.e. if the
> > > operator does nothing, the control tuple propagates. I do think users
> > > should have control on deciding to "not propagate" or "create new" and
> in
> > > these cases they would need to do something explicit (override)?
> > >
> > > The following cases come to mind
> > > 1. Sole consumer of a particular control signal (for example end of
> file)
> > > 2. Creator of a particular control signal (start of file, or a signal
> to
> > > pause on something etc.)
> > > 3. One port on a data pipeline and other port for meta-data pipeline
> > >
> > > In the above cases emit will be decided on an output port. #1 is only
> > place
> > > where all output ports will disable the tuple, #2 and #3 most likely
> will
> > > be selective.
> > >
> > > Thks
> > > Amol
> > >
> > >
> > > On Wed, Jan 4, 2017 at 12:25 PM, Thomas Weise  wrote:
> > >
> > > > I think there is (1) implicit propagation just like other control
> > tuples
> > > > where the operator code isn't involved and (2) where the operator
> > > developer
> > > > wants to decide how control tuples are created or routed and will
> > receive
> > > > and emit them on the output ports as desired.
> > > >
> > > > I don't see a use case for hybrid approaches? Maybe propagation does
> > not
> > > > need to be tied to ports at all, maybe just by annotation at the
> > operator
> > > > level?
> > > >
> > > > Thomas
> > > >
> > > >
> > > > On Wed, Jan 4, 2017 at 10:59 AM, Bhupesh Chawda <
> > bhup...@datatorrent.com
> > > >
> > > > wrote:
> > > >
> > > > > Wouldn't having this with output ports give a finer control on the
> > > > > propagation of control tuples?
> > > > > We might have an operator with two output ports each of which
> creates
> > > two
> > > > > different pipelines downstream. We would be able to say that one
> > > pipeline
> > > > > gets the control tuples and the other doesn't.
> > > > >
> > > > > ~ Bhupesh
> > > > >
> > > > >
> > > > > On Jan 4, 2017 11:55 PM, "Thomas Weise"  wrote:
> > > > >
> > > > > I'm referring to the operator that needs to make the decision to
> > > > propagate
> > > > > or not. The tuples come from an input port, so it seems
appropriate
> > to
> > > > say
> > > > > "don't propagate control tuples from this port". No matter how
many
> > > > output
> > > > > 

Re: [DISCUSS] Custom Control Tuples Design

[Thomas Weise]

I think it is important to be clear on the roles with regard to this
functionality. The user of the operator should not have to do anything to
get it to work. So while I suggested to consider attributes earlier, there
should not be any need for the user to set those. The operator needs to
work as is.

The persona concerned with propagation of control tuples is the operator
developer. I think the clear way for the operator developer to override the
propagation behavior is in code and if that is possible there is no need
for other things such as attributes or other port level settings.

Thomas


On Wed, Jan 4, 2017 at 10:20 PM, Bhupesh Chawda 
wrote:

> I think we all agree on the use case for selective propagation. The
> question is about where to have the control - at the operator level or at
> the port level.
>
> For this ability, we have the following options:
>
>1. Operator disables the propagation on selected output ports. Other
>output ports propagate by default.
>2. Operator disables propagation for the entire operator (by means of an
>attribute). Operator developer explicitly emits the received control
> tuples
>on selected output ports.
>
> If the decision is to completely block the propagation, then Option 2 is
> easier to use as just an attribute needs to be set, as opposed to Option 1
> where user needs to set the annotation on each output port.
>
> However, if selective propagation is needed, Option 1 would just need the
> user to disable propagation on certain ports; rest are propagated by
> default, while Option 2 requires the user to explicitly emit the control
> tuples.
> ~ Bhupesh
>
>
> On Thu, Jan 5, 2017 at 3:46 AM, Thomas Weise  wrote:
>
> > Yes, I think that for any of these cases the operator developer will turn
> > of implicit propagation for the operator and then write the code to route
> > or create control tuples as needed.
> >
> > Thomas
> >
> > On Wed, Jan 4, 2017 at 12:59 PM, Amol Kekre 
> wrote:
> >
> > > I agree that by default the propagation must be implicit, i.e. if the
> > > operator does nothing, the control tuple propagates. I do think users
> > > should have control on deciding to "not propagate" or "create new" and
> in
> > > these cases they would need to do something explicit (override)?
> > >
> > > The following cases come to mind
> > > 1. Sole consumer of a particular control signal (for example end of
> file)
> > > 2. Creator of a particular control signal (start of file, or a signal
> to
> > > pause on something etc.)
> > > 3. One port on a data pipeline and other port for meta-data pipeline
> > >
> > > In the above cases emit will be decided on an output port. #1 is only
> > place
> > > where all output ports will disable the tuple, #2 and #3 most likely
> will
> > > be selective.
> > >
> > > Thks
> > > Amol
> > >
> > >
> > > On Wed, Jan 4, 2017 at 12:25 PM, Thomas Weise  wrote:
> > >
> > > > I think there is (1) implicit propagation just like other control
> > tuples
> > > > where the operator code isn't involved and (2) where the operator
> > > developer
> > > > wants to decide how control tuples are created or routed and will
> > receive
> > > > and emit them on the output ports as desired.
> > > >
> > > > I don't see a use case for hybrid approaches? Maybe propagation does
> > not
> > > > need to be tied to ports at all, maybe just by annotation at the
> > operator
> > > > level?
> > > >
> > > > Thomas
> > > >
> > > >
> > > > On Wed, Jan 4, 2017 at 10:59 AM, Bhupesh Chawda <
> > bhup...@datatorrent.com
> > > >
> > > > wrote:
> > > >
> > > > > Wouldn't having this with output ports give a finer control on the
> > > > > propagation of control tuples?
> > > > > We might have an operator with two output ports each of which
> creates
> > > two
> > > > > different pipelines downstream. We would be able to say that one
> > > pipeline
> > > > > gets the control tuples and the other doesn't.
> > > > >
> > > > > ~ Bhupesh
> > > > >
> > > > >
> > > > > On Jan 4, 2017 11:55 PM, "Thomas Weise"  wrote:
> > > > >
> > > > > I'm referring to the operator that needs to make the decision to
> > > > propagate
> > > > > or not. The tuples come from an input port, so it seems appropriate
> > to
> > > > say
> > > > > "don't propagate control tuples from this port". No matter how many
> > > > output
> > > > > ports there are.
> > > > >
> > > > > Output ports are there for an operator to emit new tuples, in the
> > case
> > > > you
> > > > > are discussing you don't emit new control tuples.
> > > > >
> > > > > Thomas
> > > > >
> > > > >
> > > > > On Wed, Jan 4, 2017 at 9:39 AM, Bhupesh Chawda <
> > > bhup...@datatorrent.com>
> > > > > wrote:
> > > > >
> > > > > > Hi Thomas,
> > > > > >
> > > > > > Are you suggesting an attribute on the input port for controlling
> > the
> > > > > > propagation of control tuples to downstream operators?
> > > > > > I think it should 

Re: [DISCUSS] Custom Control Tuples Design

[Bhupesh Chawda]

I think we all agree on the use case for selective propagation. The
question is about where to have the control - at the operator level or at
the port level.

For this ability, we have the following options:

   1. Operator disables the propagation on selected output ports. Other
   output ports propagate by default.
   2. Operator disables propagation for the entire operator (by means of an
   attribute). Operator developer explicitly emits the received control tuples
   on selected output ports.

If the decision is to completely block the propagation, then Option 2 is
easier to use as just an attribute needs to be set, as opposed to Option 1
where user needs to set the annotation on each output port.

However, if selective propagation is needed, Option 1 would just need the
user to disable propagation on certain ports; rest are propagated by
default, while Option 2 requires the user to explicitly emit the control
tuples.
~ Bhupesh


On Thu, Jan 5, 2017 at 3:46 AM, Thomas Weise  wrote:

> Yes, I think that for any of these cases the operator developer will turn
> of implicit propagation for the operator and then write the code to route
> or create control tuples as needed.
>
> Thomas
>
> On Wed, Jan 4, 2017 at 12:59 PM, Amol Kekre  wrote:
>
> > I agree that by default the propagation must be implicit, i.e. if the
> > operator does nothing, the control tuple propagates. I do think users
> > should have control on deciding to "not propagate" or "create new" and in
> > these cases they would need to do something explicit (override)?
> >
> > The following cases come to mind
> > 1. Sole consumer of a particular control signal (for example end of file)
> > 2. Creator of a particular control signal (start of file, or a signal to
> > pause on something etc.)
> > 3. One port on a data pipeline and other port for meta-data pipeline
> >
> > In the above cases emit will be decided on an output port. #1 is only
> place
> > where all output ports will disable the tuple, #2 and #3 most likely will
> > be selective.
> >
> > Thks
> > Amol
> >
> >
> > On Wed, Jan 4, 2017 at 12:25 PM, Thomas Weise  wrote:
> >
> > > I think there is (1) implicit propagation just like other control
> tuples
> > > where the operator code isn't involved and (2) where the operator
> > developer
> > > wants to decide how control tuples are created or routed and will
> receive
> > > and emit them on the output ports as desired.
> > >
> > > I don't see a use case for hybrid approaches? Maybe propagation does
> not
> > > need to be tied to ports at all, maybe just by annotation at the
> operator
> > > level?
> > >
> > > Thomas
> > >
> > >
> > > On Wed, Jan 4, 2017 at 10:59 AM, Bhupesh Chawda <
> bhup...@datatorrent.com
> > >
> > > wrote:
> > >
> > > > Wouldn't having this with output ports give a finer control on the
> > > > propagation of control tuples?
> > > > We might have an operator with two output ports each of which creates
> > two
> > > > different pipelines downstream. We would be able to say that one
> > pipeline
> > > > gets the control tuples and the other doesn't.
> > > >
> > > > ~ Bhupesh
> > > >
> > > >
> > > > On Jan 4, 2017 11:55 PM, "Thomas Weise"  wrote:
> > > >
> > > > I'm referring to the operator that needs to make the decision to
> > > propagate
> > > > or not. The tuples come from an input port, so it seems appropriate
> to
> > > say
> > > > "don't propagate control tuples from this port". No matter how many
> > > output
> > > > ports there are.
> > > >
> > > > Output ports are there for an operator to emit new tuples, in the
> case
> > > you
> > > > are discussing you don't emit new control tuples.
> > > >
> > > > Thomas
> > > >
> > > >
> > > > On Wed, Jan 4, 2017 at 9:39 AM, Bhupesh Chawda <
> > bhup...@datatorrent.com>
> > > > wrote:
> > > >
> > > > > Hi Thomas,
> > > > >
> > > > > Are you suggesting an attribute on the input port for controlling
> the
> > > > > propagation of control tuples to downstream operators?
> > > > > I think it should be better to do it on the output port since the
> > > > decision
> > > > > to block the propagation will be made at the upstream operator
> rather
> > > > than
> > > > > at the downstream.
> > > > > Also, we need another way of controlling the propagation at run
> time
> > > and
> > > > > hence I was thinking about the method call on the output port, in
> > > > addition
> > > > > to the annotation on the output port (which is the static way).
> > > > >
> > > > > Please correct me if I have misunderstood your question.
> > > > >
> > > > > ~ Bhupesh
> > > > >
> > > > > On Wed, Jan 4, 2017 at 7:26 PM, Thomas Weise 
> wrote:
> > > > >
> > > > > > Wouldn't it be more intuitive to control this with an attribute
> on
> > > the
> > > > > > input port?
> > > > > >
> > > > > >
> > > > > > On Tue, Jan 3, 2017 at 11:06 PM, Bhupesh Chawda <
> > > > bhup...@datatorrent.com
> > > > > >
> > > > > > wrote:
> > 

Re: [DISCUSS] Custom Control Tuples Design

[Thomas Weise]

Yes, I think that for any of these cases the operator developer will turn
of implicit propagation for the operator and then write the code to route
or create control tuples as needed.

Thomas

On Wed, Jan 4, 2017 at 12:59 PM, Amol Kekre  wrote:

> I agree that by default the propagation must be implicit, i.e. if the
> operator does nothing, the control tuple propagates. I do think users
> should have control on deciding to "not propagate" or "create new" and in
> these cases they would need to do something explicit (override)?
>
> The following cases come to mind
> 1. Sole consumer of a particular control signal (for example end of file)
> 2. Creator of a particular control signal (start of file, or a signal to
> pause on something etc.)
> 3. One port on a data pipeline and other port for meta-data pipeline
>
> In the above cases emit will be decided on an output port. #1 is only place
> where all output ports will disable the tuple, #2 and #3 most likely will
> be selective.
>
> Thks
> Amol
>
>
> On Wed, Jan 4, 2017 at 12:25 PM, Thomas Weise  wrote:
>
> > I think there is (1) implicit propagation just like other control tuples
> > where the operator code isn't involved and (2) where the operator
> developer
> > wants to decide how control tuples are created or routed and will receive
> > and emit them on the output ports as desired.
> >
> > I don't see a use case for hybrid approaches? Maybe propagation does not
> > need to be tied to ports at all, maybe just by annotation at the operator
> > level?
> >
> > Thomas
> >
> >
> > On Wed, Jan 4, 2017 at 10:59 AM, Bhupesh Chawda  >
> > wrote:
> >
> > > Wouldn't having this with output ports give a finer control on the
> > > propagation of control tuples?
> > > We might have an operator with two output ports each of which creates
> two
> > > different pipelines downstream. We would be able to say that one
> pipeline
> > > gets the control tuples and the other doesn't.
> > >
> > > ~ Bhupesh
> > >
> > >
> > > On Jan 4, 2017 11:55 PM, "Thomas Weise"  wrote:
> > >
> > > I'm referring to the operator that needs to make the decision to
> > propagate
> > > or not. The tuples come from an input port, so it seems appropriate to
> > say
> > > "don't propagate control tuples from this port". No matter how many
> > output
> > > ports there are.
> > >
> > > Output ports are there for an operator to emit new tuples, in the case
> > you
> > > are discussing you don't emit new control tuples.
> > >
> > > Thomas
> > >
> > >
> > > On Wed, Jan 4, 2017 at 9:39 AM, Bhupesh Chawda <
> bhup...@datatorrent.com>
> > > wrote:
> > >
> > > > Hi Thomas,
> > > >
> > > > Are you suggesting an attribute on the input port for controlling the
> > > > propagation of control tuples to downstream operators?
> > > > I think it should be better to do it on the output port since the
> > > decision
> > > > to block the propagation will be made at the upstream operator rather
> > > than
> > > > at the downstream.
> > > > Also, we need another way of controlling the propagation at run time
> > and
> > > > hence I was thinking about the method call on the output port, in
> > > addition
> > > > to the annotation on the output port (which is the static way).
> > > >
> > > > Please correct me if I have misunderstood your question.
> > > >
> > > > ~ Bhupesh
> > > >
> > > > On Wed, Jan 4, 2017 at 7:26 PM, Thomas Weise  wrote:
> > > >
> > > > > Wouldn't it be more intuitive to control this with an attribute on
> > the
> > > > > input port?
> > > > >
> > > > >
> > > > > On Tue, Jan 3, 2017 at 11:06 PM, Bhupesh Chawda <
> > > bhup...@datatorrent.com
> > > > >
> > > > > wrote:
> > > > >
> > > > > > Hi Pramod,
> > > > > >
> > > > > > I was thinking of a method setPropagateControlTuples(boolean
> > > > propagate)
> > > > > on
> > > > > > the output port of the operator.
> > > > > > The operator could disable this in the code at any point of time.
> > > > > > Note however that this is to block the propagation of control
> > tuples
> > > > from
> > > > > > upstream. Any control tuples emitted explicitly by the operator
> > would
> > > > > still
> > > > > > be emitted and sent to the downstream operators.
> > > > > >
> > > > > > Please see
> > > > > > https://github.com/apache/apex-core/pull/440/files#diff-
> > > > > > 8aa0ca1a3e645fa60e9b376c118c00a3R68
> > > > > > in the PR.
> > > > > >
> > > > > > ~ Bhupesh
> > > > > >
> > > > > > On Wed, Jan 4, 2017 at 6:53 AM, Pramod Immaneni <
> > > > pra...@datatorrent.com>
> > > > > > wrote:
> > > > > >
> > > > > > > 2 sounds good. Have you thought about what the method would
> look
> > > > like.
> > > > > > >
> > > > > > > On Sat, Dec 31, 2016 at 8:29 PM, Bhupesh Chawda <
> > > > > bhup...@datatorrent.com
> > > > > > >
> > > > > > > wrote:
> > > > > > >
> > > > > > > > Yes, that makes sense.
> > > > > > > > We have following options:
> > > > > > > > 1. Make the annotation false 

Re: [DISCUSS] Custom Control Tuples Design

[Amol Kekre]

I agree that by default the propagation must be implicit, i.e. if the
operator does nothing, the control tuple propagates. I do think users
should have control on deciding to "not propagate" or "create new" and in
these cases they would need to do something explicit (override)?

The following cases come to mind
1. Sole consumer of a particular control signal (for example end of file)
2. Creator of a particular control signal (start of file, or a signal to
pause on something etc.)
3. One port on a data pipeline and other port for meta-data pipeline

In the above cases emit will be decided on an output port. #1 is only place
where all output ports will disable the tuple, #2 and #3 most likely will
be selective.

Thks
Amol


On Wed, Jan 4, 2017 at 12:25 PM, Thomas Weise  wrote:

> I think there is (1) implicit propagation just like other control tuples
> where the operator code isn't involved and (2) where the operator developer
> wants to decide how control tuples are created or routed and will receive
> and emit them on the output ports as desired.
>
> I don't see a use case for hybrid approaches? Maybe propagation does not
> need to be tied to ports at all, maybe just by annotation at the operator
> level?
>
> Thomas
>
>
> On Wed, Jan 4, 2017 at 10:59 AM, Bhupesh Chawda 
> wrote:
>
> > Wouldn't having this with output ports give a finer control on the
> > propagation of control tuples?
> > We might have an operator with two output ports each of which creates two
> > different pipelines downstream. We would be able to say that one pipeline
> > gets the control tuples and the other doesn't.
> >
> > ~ Bhupesh
> >
> >
> > On Jan 4, 2017 11:55 PM, "Thomas Weise"  wrote:
> >
> > I'm referring to the operator that needs to make the decision to
> propagate
> > or not. The tuples come from an input port, so it seems appropriate to
> say
> > "don't propagate control tuples from this port". No matter how many
> output
> > ports there are.
> >
> > Output ports are there for an operator to emit new tuples, in the case
> you
> > are discussing you don't emit new control tuples.
> >
> > Thomas
> >
> >
> > On Wed, Jan 4, 2017 at 9:39 AM, Bhupesh Chawda 
> > wrote:
> >
> > > Hi Thomas,
> > >
> > > Are you suggesting an attribute on the input port for controlling the
> > > propagation of control tuples to downstream operators?
> > > I think it should be better to do it on the output port since the
> > decision
> > > to block the propagation will be made at the upstream operator rather
> > than
> > > at the downstream.
> > > Also, we need another way of controlling the propagation at run time
> and
> > > hence I was thinking about the method call on the output port, in
> > addition
> > > to the annotation on the output port (which is the static way).
> > >
> > > Please correct me if I have misunderstood your question.
> > >
> > > ~ Bhupesh
> > >
> > > On Wed, Jan 4, 2017 at 7:26 PM, Thomas Weise  wrote:
> > >
> > > > Wouldn't it be more intuitive to control this with an attribute on
> the
> > > > input port?
> > > >
> > > >
> > > > On Tue, Jan 3, 2017 at 11:06 PM, Bhupesh Chawda <
> > bhup...@datatorrent.com
> > > >
> > > > wrote:
> > > >
> > > > > Hi Pramod,
> > > > >
> > > > > I was thinking of a method setPropagateControlTuples(boolean
> > > propagate)
> > > > on
> > > > > the output port of the operator.
> > > > > The operator could disable this in the code at any point of time.
> > > > > Note however that this is to block the propagation of control
> tuples
> > > from
> > > > > upstream. Any control tuples emitted explicitly by the operator
> would
> > > > still
> > > > > be emitted and sent to the downstream operators.
> > > > >
> > > > > Please see
> > > > > https://github.com/apache/apex-core/pull/440/files#diff-
> > > > > 8aa0ca1a3e645fa60e9b376c118c00a3R68
> > > > > in the PR.
> > > > >
> > > > > ~ Bhupesh
> > > > >
> > > > > On Wed, Jan 4, 2017 at 6:53 AM, Pramod Immaneni <
> > > pra...@datatorrent.com>
> > > > > wrote:
> > > > >
> > > > > > 2 sounds good. Have you thought about what the method would look
> > > like.
> > > > > >
> > > > > > On Sat, Dec 31, 2016 at 8:29 PM, Bhupesh Chawda <
> > > > bhup...@datatorrent.com
> > > > > >
> > > > > > wrote:
> > > > > >
> > > > > > > Yes, that makes sense.
> > > > > > > We have following options:
> > > > > > > 1. Make the annotation false by default and force the user to
> > > forward
> > > > > the
> > > > > > > control tuples explicitly.
> > > > > > > 2. Annotation is true by default and static way of blocking
> stays
> > > as
> > > > it
> > > > > > is.
> > > > > > > We provide another way for blocking programmatically, perhaps
> by
> > > > means
> > > > > of
> > > > > > > another method call on the port.
> > > > > > >
> > > > > > > ~ Bhupesh
> > > > > > >
> > > > > > > On Dec 30, 2016 00:09, "Pramod Immaneni" <
> pra...@datatorrent.com
> > >
> > > > > wrote:
> > > > > 

Re: [DISCUSS] Custom Control Tuples Design

[Thomas Weise]

I think there is (1) implicit propagation just like other control tuples
where the operator code isn't involved and (2) where the operator developer
wants to decide how control tuples are created or routed and will receive
and emit them on the output ports as desired.

I don't see a use case for hybrid approaches? Maybe propagation does not
need to be tied to ports at all, maybe just by annotation at the operator
level?

Thomas


On Wed, Jan 4, 2017 at 10:59 AM, Bhupesh Chawda 
wrote:

> Wouldn't having this with output ports give a finer control on the
> propagation of control tuples?
> We might have an operator with two output ports each of which creates two
> different pipelines downstream. We would be able to say that one pipeline
> gets the control tuples and the other doesn't.
>
> ~ Bhupesh
>
>
> On Jan 4, 2017 11:55 PM, "Thomas Weise"  wrote:
>
> I'm referring to the operator that needs to make the decision to propagate
> or not. The tuples come from an input port, so it seems appropriate to say
> "don't propagate control tuples from this port". No matter how many output
> ports there are.
>
> Output ports are there for an operator to emit new tuples, in the case you
> are discussing you don't emit new control tuples.
>
> Thomas
>
>
> On Wed, Jan 4, 2017 at 9:39 AM, Bhupesh Chawda 
> wrote:
>
> > Hi Thomas,
> >
> > Are you suggesting an attribute on the input port for controlling the
> > propagation of control tuples to downstream operators?
> > I think it should be better to do it on the output port since the
> decision
> > to block the propagation will be made at the upstream operator rather
> than
> > at the downstream.
> > Also, we need another way of controlling the propagation at run time and
> > hence I was thinking about the method call on the output port, in
> addition
> > to the annotation on the output port (which is the static way).
> >
> > Please correct me if I have misunderstood your question.
> >
> > ~ Bhupesh
> >
> > On Wed, Jan 4, 2017 at 7:26 PM, Thomas Weise  wrote:
> >
> > > Wouldn't it be more intuitive to control this with an attribute on the
> > > input port?
> > >
> > >
> > > On Tue, Jan 3, 2017 at 11:06 PM, Bhupesh Chawda <
> bhup...@datatorrent.com
> > >
> > > wrote:
> > >
> > > > Hi Pramod,
> > > >
> > > > I was thinking of a method setPropagateControlTuples(boolean
> > propagate)
> > > on
> > > > the output port of the operator.
> > > > The operator could disable this in the code at any point of time.
> > > > Note however that this is to block the propagation of control tuples
> > from
> > > > upstream. Any control tuples emitted explicitly by the operator would
> > > still
> > > > be emitted and sent to the downstream operators.
> > > >
> > > > Please see
> > > > https://github.com/apache/apex-core/pull/440/files#diff-
> > > > 8aa0ca1a3e645fa60e9b376c118c00a3R68
> > > > in the PR.
> > > >
> > > > ~ Bhupesh
> > > >
> > > > On Wed, Jan 4, 2017 at 6:53 AM, Pramod Immaneni <
> > pra...@datatorrent.com>
> > > > wrote:
> > > >
> > > > > 2 sounds good. Have you thought about what the method would look
> > like.
> > > > >
> > > > > On Sat, Dec 31, 2016 at 8:29 PM, Bhupesh Chawda <
> > > bhup...@datatorrent.com
> > > > >
> > > > > wrote:
> > > > >
> > > > > > Yes, that makes sense.
> > > > > > We have following options:
> > > > > > 1. Make the annotation false by default and force the user to
> > forward
> > > > the
> > > > > > control tuples explicitly.
> > > > > > 2. Annotation is true by default and static way of blocking stays
> > as
> > > it
> > > > > is.
> > > > > > We provide another way for blocking programmatically, perhaps by
> > > means
> > > > of
> > > > > > another method call on the port.
> > > > > >
> > > > > > ~ Bhupesh
> > > > > >
> > > > > > On Dec 30, 2016 00:09, "Pramod Immaneni"  >
> > > > wrote:
> > > > > >
> > > > > > > Bhupesh,
> > > > > > >
> > > > > > > Annotation seems like a static way to stop propagation. Give
> > these
> > > > are
> > > > > > > programmatically generated I would think the operators should
> be
> > > able
> > > > > to
> > > > > > > stop (consume without propagating) programmatically as well.
> > > > > > >
> > > > > > > Thanks
> > > > > > >
> > > > > > > On Thu, Dec 29, 2016 at 8:48 AM, Bhupesh Chawda <
> > > > > bhup...@datatorrent.com
> > > > > > >
> > > > > > > wrote:
> > > > > > >
> > > > > > > > Thanks Vlad, I am trying out the approach you mentioned
> > regarding
> > > > > > having
> > > > > > > > another interface which allows sinks to put a control tuple.
> > > > > > > >
> > > > > > > > Regarding the delivery of control tuples, here is what I am
> > > > planning
> > > > > to
> > > > > > > do:
> > > > > > > > All the control tuples which are emitted in a particular
> window
> > > are
> > > > > > > > delivered after all the data tuples have been delivered to
> the
> > > > > > respective
> > > > > > > > ports, but before 

Re: [DISCUSS] Custom Control Tuples Design

[Amol Kekre]

Yes, there is a chance that two output ports will have different send
requirements.

Thks
Amol


On Wed, Jan 4, 2017 at 10:59 AM, Bhupesh Chawda 
wrote:

> Wouldn't having this with output ports give a finer control on the
> propagation of control tuples?
> We might have an operator with two output ports each of which creates two
> different pipelines downstream. We would be able to say that one pipeline
> gets the control tuples and the other doesn't.
>
> ~ Bhupesh
>
>
> On Jan 4, 2017 11:55 PM, "Thomas Weise"  wrote:
>
> I'm referring to the operator that needs to make the decision to propagate
> or not. The tuples come from an input port, so it seems appropriate to say
> "don't propagate control tuples from this port". No matter how many output
> ports there are.
>
> Output ports are there for an operator to emit new tuples, in the case you
> are discussing you don't emit new control tuples.
>
> Thomas
>
>
> On Wed, Jan 4, 2017 at 9:39 AM, Bhupesh Chawda 
> wrote:
>
> > Hi Thomas,
> >
> > Are you suggesting an attribute on the input port for controlling the
> > propagation of control tuples to downstream operators?
> > I think it should be better to do it on the output port since the
> decision
> > to block the propagation will be made at the upstream operator rather
> than
> > at the downstream.
> > Also, we need another way of controlling the propagation at run time and
> > hence I was thinking about the method call on the output port, in
> addition
> > to the annotation on the output port (which is the static way).
> >
> > Please correct me if I have misunderstood your question.
> >
> > ~ Bhupesh
> >
> > On Wed, Jan 4, 2017 at 7:26 PM, Thomas Weise  wrote:
> >
> > > Wouldn't it be more intuitive to control this with an attribute on the
> > > input port?
> > >
> > >
> > > On Tue, Jan 3, 2017 at 11:06 PM, Bhupesh Chawda <
> bhup...@datatorrent.com
> > >
> > > wrote:
> > >
> > > > Hi Pramod,
> > > >
> > > > I was thinking of a method setPropagateControlTuples(boolean
> > propagate)
> > > on
> > > > the output port of the operator.
> > > > The operator could disable this in the code at any point of time.
> > > > Note however that this is to block the propagation of control tuples
> > from
> > > > upstream. Any control tuples emitted explicitly by the operator would
> > > still
> > > > be emitted and sent to the downstream operators.
> > > >
> > > > Please see
> > > > https://github.com/apache/apex-core/pull/440/files#diff-
> > > > 8aa0ca1a3e645fa60e9b376c118c00a3R68
> > > > in the PR.
> > > >
> > > > ~ Bhupesh
> > > >
> > > > On Wed, Jan 4, 2017 at 6:53 AM, Pramod Immaneni <
> > pra...@datatorrent.com>
> > > > wrote:
> > > >
> > > > > 2 sounds good. Have you thought about what the method would look
> > like.
> > > > >
> > > > > On Sat, Dec 31, 2016 at 8:29 PM, Bhupesh Chawda <
> > > bhup...@datatorrent.com
> > > > >
> > > > > wrote:
> > > > >
> > > > > > Yes, that makes sense.
> > > > > > We have following options:
> > > > > > 1. Make the annotation false by default and force the user to
> > forward
> > > > the
> > > > > > control tuples explicitly.
> > > > > > 2. Annotation is true by default and static way of blocking stays
> > as
> > > it
> > > > > is.
> > > > > > We provide another way for blocking programmatically, perhaps by
> > > means
> > > > of
> > > > > > another method call on the port.
> > > > > >
> > > > > > ~ Bhupesh
> > > > > >
> > > > > > On Dec 30, 2016 00:09, "Pramod Immaneni"  >
> > > > wrote:
> > > > > >
> > > > > > > Bhupesh,
> > > > > > >
> > > > > > > Annotation seems like a static way to stop propagation. Give
> > these
> > > > are
> > > > > > > programmatically generated I would think the operators should
> be
> > > able
> > > > > to
> > > > > > > stop (consume without propagating) programmatically as well.
> > > > > > >
> > > > > > > Thanks
> > > > > > >
> > > > > > > On Thu, Dec 29, 2016 at 8:48 AM, Bhupesh Chawda <
> > > > > bhup...@datatorrent.com
> > > > > > >
> > > > > > > wrote:
> > > > > > >
> > > > > > > > Thanks Vlad, I am trying out the approach you mentioned
> > regarding
> > > > > > having
> > > > > > > > another interface which allows sinks to put a control tuple.
> > > > > > > >
> > > > > > > > Regarding the delivery of control tuples, here is what I am
> > > > planning
> > > > > to
> > > > > > > do:
> > > > > > > > All the control tuples which are emitted in a particular
> window
> > > are
> > > > > > > > delivered after all the data tuples have been delivered to
> the
> > > > > > respective
> > > > > > > > ports, but before the endWindow() call. The operator can then
> > > > process
> > > > > > the
> > > > > > > > control tuples in that window and can do any finalization in
> > the
> > > > end
> > > > > > > window
> > > > > > > > call. There will be no delivery of control tuples after
> > > endWindow()
> > > > > and
> > > > > > > > before the next 

Re: [DISCUSS] Custom Control Tuples Design

[Bhupesh Chawda]

Wouldn't having this with output ports give a finer control on the
propagation of control tuples?
We might have an operator with two output ports each of which creates two
different pipelines downstream. We would be able to say that one pipeline
gets the control tuples and the other doesn't.

~ Bhupesh


On Jan 4, 2017 11:55 PM, "Thomas Weise"  wrote:

I'm referring to the operator that needs to make the decision to propagate
or not. The tuples come from an input port, so it seems appropriate to say
"don't propagate control tuples from this port". No matter how many output
ports there are.

Output ports are there for an operator to emit new tuples, in the case you
are discussing you don't emit new control tuples.

Thomas


On Wed, Jan 4, 2017 at 9:39 AM, Bhupesh Chawda 
wrote:

> Hi Thomas,
>
> Are you suggesting an attribute on the input port for controlling the
> propagation of control tuples to downstream operators?
> I think it should be better to do it on the output port since the decision
> to block the propagation will be made at the upstream operator rather than
> at the downstream.
> Also, we need another way of controlling the propagation at run time and
> hence I was thinking about the method call on the output port, in addition
> to the annotation on the output port (which is the static way).
>
> Please correct me if I have misunderstood your question.
>
> ~ Bhupesh
>
> On Wed, Jan 4, 2017 at 7:26 PM, Thomas Weise  wrote:
>
> > Wouldn't it be more intuitive to control this with an attribute on the
> > input port?
> >
> >
> > On Tue, Jan 3, 2017 at 11:06 PM, Bhupesh Chawda  >
> > wrote:
> >
> > > Hi Pramod,
> > >
> > > I was thinking of a method setPropagateControlTuples(boolean
> propagate)
> > on
> > > the output port of the operator.
> > > The operator could disable this in the code at any point of time.
> > > Note however that this is to block the propagation of control tuples
> from
> > > upstream. Any control tuples emitted explicitly by the operator would
> > still
> > > be emitted and sent to the downstream operators.
> > >
> > > Please see
> > > https://github.com/apache/apex-core/pull/440/files#diff-
> > > 8aa0ca1a3e645fa60e9b376c118c00a3R68
> > > in the PR.
> > >
> > > ~ Bhupesh
> > >
> > > On Wed, Jan 4, 2017 at 6:53 AM, Pramod Immaneni <
> pra...@datatorrent.com>
> > > wrote:
> > >
> > > > 2 sounds good. Have you thought about what the method would look
> like.
> > > >
> > > > On Sat, Dec 31, 2016 at 8:29 PM, Bhupesh Chawda <
> > bhup...@datatorrent.com
> > > >
> > > > wrote:
> > > >
> > > > > Yes, that makes sense.
> > > > > We have following options:
> > > > > 1. Make the annotation false by default and force the user to
> forward
> > > the
> > > > > control tuples explicitly.
> > > > > 2. Annotation is true by default and static way of blocking stays
> as
> > it
> > > > is.
> > > > > We provide another way for blocking programmatically, perhaps by
> > means
> > > of
> > > > > another method call on the port.
> > > > >
> > > > > ~ Bhupesh
> > > > >
> > > > > On Dec 30, 2016 00:09, "Pramod Immaneni" 
> > > wrote:
> > > > >
> > > > > > Bhupesh,
> > > > > >
> > > > > > Annotation seems like a static way to stop propagation. Give
> these
> > > are
> > > > > > programmatically generated I would think the operators should be
> > able
> > > > to
> > > > > > stop (consume without propagating) programmatically as well.
> > > > > >
> > > > > > Thanks
> > > > > >
> > > > > > On Thu, Dec 29, 2016 at 8:48 AM, Bhupesh Chawda <
> > > > bhup...@datatorrent.com
> > > > > >
> > > > > > wrote:
> > > > > >
> > > > > > > Thanks Vlad, I am trying out the approach you mentioned
> regarding
> > > > > having
> > > > > > > another interface which allows sinks to put a control tuple.
> > > > > > >
> > > > > > > Regarding the delivery of control tuples, here is what I am
> > > planning
> > > > to
> > > > > > do:
> > > > > > > All the control tuples which are emitted in a particular
window
> > are
> > > > > > > delivered after all the data tuples have been delivered to the
> > > > > respective
> > > > > > > ports, but before the endWindow() call. The operator can then
> > > process
> > > > > the
> > > > > > > control tuples in that window and can do any finalization in
> the
> > > end
> > > > > > window
> > > > > > > call. There will be no delivery of control tuples after
> > endWindow()
> > > > and
> > > > > > > before the next beginWindow() call.
> > > > > > >
> > > > > > > For handling the propagation of control tuples further in the
> > dag,
> > > we
> > > > > are
> > > > > > > planning to have an annotation on the Output Port of the
> operator
> > > > which
> > > > > > > would be true by default.
> > > > > > > @OutputPortFieldAnnotation(propogateControlTuples = false).
> > > > > > >
> > > > > > > ~ Bhupesh
> > > > > > >
> > > > > > >
> > > > > > > On Thu, Dec 29, 2016 at 6:24 AM, Vlad Rozov <
> > 

Re: [DISCUSS] Custom Control Tuples Design

[Thomas Weise]

I'm referring to the operator that needs to make the decision to propagate
or not. The tuples come from an input port, so it seems appropriate to say
"don't propagate control tuples from this port". No matter how many output
ports there are.

Output ports are there for an operator to emit new tuples, in the case you
are discussing you don't emit new control tuples.

Thomas


On Wed, Jan 4, 2017 at 9:39 AM, Bhupesh Chawda 
wrote:

> Hi Thomas,
>
> Are you suggesting an attribute on the input port for controlling the
> propagation of control tuples to downstream operators?
> I think it should be better to do it on the output port since the decision
> to block the propagation will be made at the upstream operator rather than
> at the downstream.
> Also, we need another way of controlling the propagation at run time and
> hence I was thinking about the method call on the output port, in addition
> to the annotation on the output port (which is the static way).
>
> Please correct me if I have misunderstood your question.
>
> ~ Bhupesh
>
> On Wed, Jan 4, 2017 at 7:26 PM, Thomas Weise  wrote:
>
> > Wouldn't it be more intuitive to control this with an attribute on the
> > input port?
> >
> >
> > On Tue, Jan 3, 2017 at 11:06 PM, Bhupesh Chawda  >
> > wrote:
> >
> > > Hi Pramod,
> > >
> > > I was thinking of a method setPropagateControlTuples(boolean
> propagate)
> > on
> > > the output port of the operator.
> > > The operator could disable this in the code at any point of time.
> > > Note however that this is to block the propagation of control tuples
> from
> > > upstream. Any control tuples emitted explicitly by the operator would
> > still
> > > be emitted and sent to the downstream operators.
> > >
> > > Please see
> > > https://github.com/apache/apex-core/pull/440/files#diff-
> > > 8aa0ca1a3e645fa60e9b376c118c00a3R68
> > > in the PR.
> > >
> > > ~ Bhupesh
> > >
> > > On Wed, Jan 4, 2017 at 6:53 AM, Pramod Immaneni <
> pra...@datatorrent.com>
> > > wrote:
> > >
> > > > 2 sounds good. Have you thought about what the method would look
> like.
> > > >
> > > > On Sat, Dec 31, 2016 at 8:29 PM, Bhupesh Chawda <
> > bhup...@datatorrent.com
> > > >
> > > > wrote:
> > > >
> > > > > Yes, that makes sense.
> > > > > We have following options:
> > > > > 1. Make the annotation false by default and force the user to
> forward
> > > the
> > > > > control tuples explicitly.
> > > > > 2. Annotation is true by default and static way of blocking stays
> as
> > it
> > > > is.
> > > > > We provide another way for blocking programmatically, perhaps by
> > means
> > > of
> > > > > another method call on the port.
> > > > >
> > > > > ~ Bhupesh
> > > > >
> > > > > On Dec 30, 2016 00:09, "Pramod Immaneni" 
> > > wrote:
> > > > >
> > > > > > Bhupesh,
> > > > > >
> > > > > > Annotation seems like a static way to stop propagation. Give
> these
> > > are
> > > > > > programmatically generated I would think the operators should be
> > able
> > > > to
> > > > > > stop (consume without propagating) programmatically as well.
> > > > > >
> > > > > > Thanks
> > > > > >
> > > > > > On Thu, Dec 29, 2016 at 8:48 AM, Bhupesh Chawda <
> > > > bhup...@datatorrent.com
> > > > > >
> > > > > > wrote:
> > > > > >
> > > > > > > Thanks Vlad, I am trying out the approach you mentioned
> regarding
> > > > > having
> > > > > > > another interface which allows sinks to put a control tuple.
> > > > > > >
> > > > > > > Regarding the delivery of control tuples, here is what I am
> > > planning
> > > > to
> > > > > > do:
> > > > > > > All the control tuples which are emitted in a particular window
> > are
> > > > > > > delivered after all the data tuples have been delivered to the
> > > > > respective
> > > > > > > ports, but before the endWindow() call. The operator can then
> > > process
> > > > > the
> > > > > > > control tuples in that window and can do any finalization in
> the
> > > end
> > > > > > window
> > > > > > > call. There will be no delivery of control tuples after
> > endWindow()
> > > > and
> > > > > > > before the next beginWindow() call.
> > > > > > >
> > > > > > > For handling the propagation of control tuples further in the
> > dag,
> > > we
> > > > > are
> > > > > > > planning to have an annotation on the Output Port of the
> operator
> > > > which
> > > > > > > would be true by default.
> > > > > > > @OutputPortFieldAnnotation(propogateControlTuples = false).
> > > > > > >
> > > > > > > ~ Bhupesh
> > > > > > >
> > > > > > >
> > > > > > > On Thu, Dec 29, 2016 at 6:24 AM, Vlad Rozov <
> > > v.ro...@datatorrent.com
> > > > >
> > > > > > > wrote:
> > > > > > >
> > > > > > > > Custom control tuples are control tuples emitted by an
> operator
> > > > > itself
> > > > > > > and
> > > > > > > > not by the platform. Prior to the introduction of the custom
> > > > control
> > > > > > > > tuples, only Apex engine itself puts control tuples into
> > various
> > > 

Re: [DISCUSS] Custom Control Tuples Design

[Thomas Weise]

Wouldn't it be more intuitive to control this with an attribute on the
input port?


On Tue, Jan 3, 2017 at 11:06 PM, Bhupesh Chawda 
wrote:

> Hi Pramod,
>
> I was thinking of a method setPropagateControlTuples(boolean propagate) on
> the output port of the operator.
> The operator could disable this in the code at any point of time.
> Note however that this is to block the propagation of control tuples from
> upstream. Any control tuples emitted explicitly by the operator would still
> be emitted and sent to the downstream operators.
>
> Please see
> https://github.com/apache/apex-core/pull/440/files#diff-
> 8aa0ca1a3e645fa60e9b376c118c00a3R68
> in the PR.
>
> ~ Bhupesh
>
> On Wed, Jan 4, 2017 at 6:53 AM, Pramod Immaneni 
> wrote:
>
> > 2 sounds good. Have you thought about what the method would look like.
> >
> > On Sat, Dec 31, 2016 at 8:29 PM, Bhupesh Chawda  >
> > wrote:
> >
> > > Yes, that makes sense.
> > > We have following options:
> > > 1. Make the annotation false by default and force the user to forward
> the
> > > control tuples explicitly.
> > > 2. Annotation is true by default and static way of blocking stays as it
> > is.
> > > We provide another way for blocking programmatically, perhaps by means
> of
> > > another method call on the port.
> > >
> > > ~ Bhupesh
> > >
> > > On Dec 30, 2016 00:09, "Pramod Immaneni" 
> wrote:
> > >
> > > > Bhupesh,
> > > >
> > > > Annotation seems like a static way to stop propagation. Give these
> are
> > > > programmatically generated I would think the operators should be able
> > to
> > > > stop (consume without propagating) programmatically as well.
> > > >
> > > > Thanks
> > > >
> > > > On Thu, Dec 29, 2016 at 8:48 AM, Bhupesh Chawda <
> > bhup...@datatorrent.com
> > > >
> > > > wrote:
> > > >
> > > > > Thanks Vlad, I am trying out the approach you mentioned regarding
> > > having
> > > > > another interface which allows sinks to put a control tuple.
> > > > >
> > > > > Regarding the delivery of control tuples, here is what I am
> planning
> > to
> > > > do:
> > > > > All the control tuples which are emitted in a particular window are
> > > > > delivered after all the data tuples have been delivered to the
> > > respective
> > > > > ports, but before the endWindow() call. The operator can then
> process
> > > the
> > > > > control tuples in that window and can do any finalization in the
> end
> > > > window
> > > > > call. There will be no delivery of control tuples after endWindow()
> > and
> > > > > before the next beginWindow() call.
> > > > >
> > > > > For handling the propagation of control tuples further in the dag,
> we
> > > are
> > > > > planning to have an annotation on the Output Port of the operator
> > which
> > > > > would be true by default.
> > > > > @OutputPortFieldAnnotation(propogateControlTuples = false).
> > > > >
> > > > > ~ Bhupesh
> > > > >
> > > > >
> > > > > On Thu, Dec 29, 2016 at 6:24 AM, Vlad Rozov <
> v.ro...@datatorrent.com
> > >
> > > > > wrote:
> > > > >
> > > > > > Custom control tuples are control tuples emitted by an operator
> > > itself
> > > > > and
> > > > > > not by the platform. Prior to the introduction of the custom
> > control
> > > > > > tuples, only Apex engine itself puts control tuples into various
> > > sinks,
> > > > > so
> > > > > > the engine created necessary Tuple objects with the corresponding
> > > type
> > > > > > prior to calling Sink.put().
> > > > > >
> > > > > > Not all sinks need to be changed. Only control tuple aware sinks
> > > should
> > > > > > provide such functionality. In the case there is a lot of code
> > > > > duplication,
> > > > > > please create an abstract class, that other control aware sinks
> > will
> > > > > extend
> > > > > > from.
> > > > > >
> > > > > > Thank you,
> > > > > >
> > > > > > Vlad
> > > > > >
> > > > > >
> > > > > > On 12/23/16 06:24, Bhupesh Chawda wrote:
> > > > > >
> > > > > >> Hi Vlad,
> > > > > >>
> > > > > >> Thanks for the pointer on delegating the wrapping of the user
> > tuple
> > > to
> > > > > the
> > > > > >> control port. I was trying this out today.
> > > > > >> The problem I see us if we introduce a putControlTuple() method
> in
> > > > Sink,
> > > > > >> then a lot of the existing sinks would change. Also the changes
> > > seemed
> > > > > >> redundant as, the existing control tuples already use the put()
> > > method
> > > > > of
> > > > > >> sinks. So why do something special for custom control tuples?
> > > > > >>
> > > > > >> The only aspect in which the custom control tuples are different
> > is
> > > > that
> > > > > >> these will be generated by the user and will actually be
> delivered
> > > to
> > > > > the
> > > > > >> ports in a different order. Perhaps we should be able to use the
> > > > > existing
> > > > > >> flow. The only problems as outlined before seem to be
> > identification
> > > > of
> > > > > >> the
> > > > > >> user 

Re: [DISCUSS] Custom Control Tuples Design

[Pramod Immaneni]

2 sounds good. Have you thought about what the method would look like.

On Sat, Dec 31, 2016 at 8:29 PM, Bhupesh Chawda 
wrote:

> Yes, that makes sense.
> We have following options:
> 1. Make the annotation false by default and force the user to forward the
> control tuples explicitly.
> 2. Annotation is true by default and static way of blocking stays as it is.
> We provide another way for blocking programmatically, perhaps by means of
> another method call on the port.
>
> ~ Bhupesh
>
> On Dec 30, 2016 00:09, "Pramod Immaneni"  wrote:
>
> > Bhupesh,
> >
> > Annotation seems like a static way to stop propagation. Give these are
> > programmatically generated I would think the operators should be able to
> > stop (consume without propagating) programmatically as well.
> >
> > Thanks
> >
> > On Thu, Dec 29, 2016 at 8:48 AM, Bhupesh Chawda  >
> > wrote:
> >
> > > Thanks Vlad, I am trying out the approach you mentioned regarding
> having
> > > another interface which allows sinks to put a control tuple.
> > >
> > > Regarding the delivery of control tuples, here is what I am planning to
> > do:
> > > All the control tuples which are emitted in a particular window are
> > > delivered after all the data tuples have been delivered to the
> respective
> > > ports, but before the endWindow() call. The operator can then process
> the
> > > control tuples in that window and can do any finalization in the end
> > window
> > > call. There will be no delivery of control tuples after endWindow() and
> > > before the next beginWindow() call.
> > >
> > > For handling the propagation of control tuples further in the dag, we
> are
> > > planning to have an annotation on the Output Port of the operator which
> > > would be true by default.
> > > @OutputPortFieldAnnotation(propogateControlTuples = false).
> > >
> > > ~ Bhupesh
> > >
> > >
> > > On Thu, Dec 29, 2016 at 6:24 AM, Vlad Rozov 
> > > wrote:
> > >
> > > > Custom control tuples are control tuples emitted by an operator
> itself
> > > and
> > > > not by the platform. Prior to the introduction of the custom control
> > > > tuples, only Apex engine itself puts control tuples into various
> sinks,
> > > so
> > > > the engine created necessary Tuple objects with the corresponding
> type
> > > > prior to calling Sink.put().
> > > >
> > > > Not all sinks need to be changed. Only control tuple aware sinks
> should
> > > > provide such functionality. In the case there is a lot of code
> > > duplication,
> > > > please create an abstract class, that other control aware sinks will
> > > extend
> > > > from.
> > > >
> > > > Thank you,
> > > >
> > > > Vlad
> > > >
> > > >
> > > > On 12/23/16 06:24, Bhupesh Chawda wrote:
> > > >
> > > >> Hi Vlad,
> > > >>
> > > >> Thanks for the pointer on delegating the wrapping of the user tuple
> to
> > > the
> > > >> control port. I was trying this out today.
> > > >> The problem I see us if we introduce a putControlTuple() method in
> > Sink,
> > > >> then a lot of the existing sinks would change. Also the changes
> seemed
> > > >> redundant as, the existing control tuples already use the put()
> method
> > > of
> > > >> sinks. So why do something special for custom control tuples?
> > > >>
> > > >> The only aspect in which the custom control tuples are different is
> > that
> > > >> these will be generated by the user and will actually be delivered
> to
> > > the
> > > >> ports in a different order. Perhaps we should be able to use the
> > > existing
> > > >> flow. The only problems as outlined before seem to be identification
> > of
> > > >> the
> > > >> user tuple as a control tuple.
> > > >>
> > > >> ~ Bhupesh
> > > >>
> > > >>
> > > >> On Thu, Dec 22, 2016 at 10:44 PM, Vlad Rozov <
> v.ro...@datatorrent.com
> > >
> > > >> wrote:
> > > >>
> > > >> Why is it necessary to wrap in the OutputPort? Can't it be delegated
> > to
> > > a
> > > >>> Sink by introducing new putControlTuple method?
> > > >>>
> > > >>> Thank you,
> > > >>>
> > > >>> Vlad
> > > >>>
> > > >>>
> > > >>> On 12/21/16 22:10, Bhupesh Chawda wrote:
> > > >>>
> > > >>> Hi Vlad,
> > > 
> > >  The problem in using the Tuple class as the wrapper is that the
> > Ports
> > >  belong to the API and we want to wrap the payload object of the
> > > control
> > >  tuple into the Tuple class which is not part of the API.
> > > 
> > >  The output port will just get the payload of the user control
> tuple.
> > > For
> > >  example, if the user emits a Long, as a control tuple, the payload
> > >  object
> > >  will just be a Long object.
> > > 
> > >  It is necessary to bundle this Long into some recognizable object
> so
> > >  that
> > >  the BufferServerPublisher knows that this is a Control tuple and
> > not a
> > >  regular tuple and serialize it accordingly. It is therefore
> > necessary
> > >  that
> > >  the tuple be part 

Re: [DISCUSS] Custom Control Tuples Design

[Bhupesh Chawda]

Yes David, that is correct.
The annotation is true by default.

However, it may happen that in the course of processing, we may want to
stop the propagation of control tuples to the downstream operators. In this
case, we should have an option to block the control tuples propagation to
downstream operators based on a runtime condition.

~ Bhupesh

On Jan 3, 2017 23:04, "David Yan"  wrote:

> The annotation should be true by default. If an operator does not care
> about the control tuples, it should propagate them because the downstream
> might care about it. For example, let's say the original DAG looks like:
>
> A->B
>
> And A emits control tuples that B cares about, and of course along with
> other data tuples. Now I want to change the DAG and insert a filter
> operator F in between A and B for filtering data tuples.
>
> A->F->B
>
> F is not aware of any control tuples because it's the business between A
> and B, and F only filters on data tuples. Should the application developer
> who inserts F have to remember that we need to annotate F so that F will
> propagate the control tuples? The answer should be no.
>
> David
>
> On Sat, Dec 31, 2016 at 8:29 PM, Bhupesh Chawda 
> wrote:
>
> > Yes, that makes sense.
> > We have following options:
> > 1. Make the annotation false by default and force the user to forward the
> > control tuples explicitly.
> > 2. Annotation is true by default and static way of blocking stays as it
> is.
> > We provide another way for blocking programmatically, perhaps by means of
> > another method call on the port.
> >
> > ~ Bhupesh
> >
> > On Dec 30, 2016 00:09, "Pramod Immaneni"  wrote:
> >
> > > Bhupesh,
> > >
> > > Annotation seems like a static way to stop propagation. Give these are
> > > programmatically generated I would think the operators should be able
> to
> > > stop (consume without propagating) programmatically as well.
> > >
> > > Thanks
> > >
> > > On Thu, Dec 29, 2016 at 8:48 AM, Bhupesh Chawda <
> bhup...@datatorrent.com
> > >
> > > wrote:
> > >
> > > > Thanks Vlad, I am trying out the approach you mentioned regarding
> > having
> > > > another interface which allows sinks to put a control tuple.
> > > >
> > > > Regarding the delivery of control tuples, here is what I am planning
> to
> > > do:
> > > > All the control tuples which are emitted in a particular window are
> > > > delivered after all the data tuples have been delivered to the
> > respective
> > > > ports, but before the endWindow() call. The operator can then process
> > the
> > > > control tuples in that window and can do any finalization in the end
> > > window
> > > > call. There will be no delivery of control tuples after endWindow()
> and
> > > > before the next beginWindow() call.
> > > >
> > > > For handling the propagation of control tuples further in the dag, we
> > are
> > > > planning to have an annotation on the Output Port of the operator
> which
> > > > would be true by default.
> > > > @OutputPortFieldAnnotation(propogateControlTuples = false).
> > > >
> > > > ~ Bhupesh
> > > >
> > > >
> > > > On Thu, Dec 29, 2016 at 6:24 AM, Vlad Rozov  >
> > > > wrote:
> > > >
> > > > > Custom control tuples are control tuples emitted by an operator
> > itself
> > > > and
> > > > > not by the platform. Prior to the introduction of the custom
> control
> > > > > tuples, only Apex engine itself puts control tuples into various
> > sinks,
> > > > so
> > > > > the engine created necessary Tuple objects with the corresponding
> > type
> > > > > prior to calling Sink.put().
> > > > >
> > > > > Not all sinks need to be changed. Only control tuple aware sinks
> > should
> > > > > provide such functionality. In the case there is a lot of code
> > > > duplication,
> > > > > please create an abstract class, that other control aware sinks
> will
> > > > extend
> > > > > from.
> > > > >
> > > > > Thank you,
> > > > >
> > > > > Vlad
> > > > >
> > > > >
> > > > > On 12/23/16 06:24, Bhupesh Chawda wrote:
> > > > >
> > > > >> Hi Vlad,
> > > > >>
> > > > >> Thanks for the pointer on delegating the wrapping of the user
> tuple
> > to
> > > > the
> > > > >> control port. I was trying this out today.
> > > > >> The problem I see us if we introduce a putControlTuple() method in
> > > Sink,
> > > > >> then a lot of the existing sinks would change. Also the changes
> > seemed
> > > > >> redundant as, the existing control tuples already use the put()
> > method
> > > > of
> > > > >> sinks. So why do something special for custom control tuples?
> > > > >>
> > > > >> The only aspect in which the custom control tuples are different
> is
> > > that
> > > > >> these will be generated by the user and will actually be delivered
> > to
> > > > the
> > > > >> ports in a different order. Perhaps we should be able to use the
> > > > existing
> > > > >> flow. The only problems as outlined before seem to be
> identification
> > > of
> > > > >> 

Re: [DISCUSS] Custom Control Tuples Design

[David Yan]

The annotation should be true by default. If an operator does not care
about the control tuples, it should propagate them because the downstream
might care about it. For example, let's say the original DAG looks like:

A->B

And A emits control tuples that B cares about, and of course along with
other data tuples. Now I want to change the DAG and insert a filter
operator F in between A and B for filtering data tuples.

A->F->B

F is not aware of any control tuples because it's the business between A
and B, and F only filters on data tuples. Should the application developer
who inserts F have to remember that we need to annotate F so that F will
propagate the control tuples? The answer should be no.

David

On Sat, Dec 31, 2016 at 8:29 PM, Bhupesh Chawda 
wrote:

> Yes, that makes sense.
> We have following options:
> 1. Make the annotation false by default and force the user to forward the
> control tuples explicitly.
> 2. Annotation is true by default and static way of blocking stays as it is.
> We provide another way for blocking programmatically, perhaps by means of
> another method call on the port.
>
> ~ Bhupesh
>
> On Dec 30, 2016 00:09, "Pramod Immaneni"  wrote:
>
> > Bhupesh,
> >
> > Annotation seems like a static way to stop propagation. Give these are
> > programmatically generated I would think the operators should be able to
> > stop (consume without propagating) programmatically as well.
> >
> > Thanks
> >
> > On Thu, Dec 29, 2016 at 8:48 AM, Bhupesh Chawda  >
> > wrote:
> >
> > > Thanks Vlad, I am trying out the approach you mentioned regarding
> having
> > > another interface which allows sinks to put a control tuple.
> > >
> > > Regarding the delivery of control tuples, here is what I am planning to
> > do:
> > > All the control tuples which are emitted in a particular window are
> > > delivered after all the data tuples have been delivered to the
> respective
> > > ports, but before the endWindow() call. The operator can then process
> the
> > > control tuples in that window and can do any finalization in the end
> > window
> > > call. There will be no delivery of control tuples after endWindow() and
> > > before the next beginWindow() call.
> > >
> > > For handling the propagation of control tuples further in the dag, we
> are
> > > planning to have an annotation on the Output Port of the operator which
> > > would be true by default.
> > > @OutputPortFieldAnnotation(propogateControlTuples = false).
> > >
> > > ~ Bhupesh
> > >
> > >
> > > On Thu, Dec 29, 2016 at 6:24 AM, Vlad Rozov 
> > > wrote:
> > >
> > > > Custom control tuples are control tuples emitted by an operator
> itself
> > > and
> > > > not by the platform. Prior to the introduction of the custom control
> > > > tuples, only Apex engine itself puts control tuples into various
> sinks,
> > > so
> > > > the engine created necessary Tuple objects with the corresponding
> type
> > > > prior to calling Sink.put().
> > > >
> > > > Not all sinks need to be changed. Only control tuple aware sinks
> should
> > > > provide such functionality. In the case there is a lot of code
> > > duplication,
> > > > please create an abstract class, that other control aware sinks will
> > > extend
> > > > from.
> > > >
> > > > Thank you,
> > > >
> > > > Vlad
> > > >
> > > >
> > > > On 12/23/16 06:24, Bhupesh Chawda wrote:
> > > >
> > > >> Hi Vlad,
> > > >>
> > > >> Thanks for the pointer on delegating the wrapping of the user tuple
> to
> > > the
> > > >> control port. I was trying this out today.
> > > >> The problem I see us if we introduce a putControlTuple() method in
> > Sink,
> > > >> then a lot of the existing sinks would change. Also the changes
> seemed
> > > >> redundant as, the existing control tuples already use the put()
> method
> > > of
> > > >> sinks. So why do something special for custom control tuples?
> > > >>
> > > >> The only aspect in which the custom control tuples are different is
> > that
> > > >> these will be generated by the user and will actually be delivered
> to
> > > the
> > > >> ports in a different order. Perhaps we should be able to use the
> > > existing
> > > >> flow. The only problems as outlined before seem to be identification
> > of
> > > >> the
> > > >> user tuple as a control tuple.
> > > >>
> > > >> ~ Bhupesh
> > > >>
> > > >>
> > > >> On Thu, Dec 22, 2016 at 10:44 PM, Vlad Rozov <
> v.ro...@datatorrent.com
> > >
> > > >> wrote:
> > > >>
> > > >> Why is it necessary to wrap in the OutputPort? Can't it be delegated
> > to
> > > a
> > > >>> Sink by introducing new putControlTuple method?
> > > >>>
> > > >>> Thank you,
> > > >>>
> > > >>> Vlad
> > > >>>
> > > >>>
> > > >>> On 12/21/16 22:10, Bhupesh Chawda wrote:
> > > >>>
> > > >>> Hi Vlad,
> > > 
> > >  The problem in using the Tuple class as the wrapper is that the
> > Ports
> > >  belong to the API and we want to wrap the payload object of the

Re: [DISCUSS] Custom Control Tuples Design

[Bhupesh Chawda]

Hi All,

I have created a review only PR based on the discussion so far.
This will also help make the discussion easier and we can continue with the
review in parallel.

Here is the PR: https://github.com/apache/apex-core/pull/440

Please help review this. I am still working on documentation and tests.

~ Bhupesh

On Sun, Jan 1, 2017 at 9:59 AM, Bhupesh Chawda 
wrote:

> Yes, that makes sense.
> We have following options:
> 1. Make the annotation false by default and force the user to forward the
> control tuples explicitly.
> 2. Annotation is true by default and static way of blocking stays as it
> is. We provide another way for blocking programmatically, perhaps by means
> of another method call on the port.
>
> ~ Bhupesh
>
> On Dec 30, 2016 00:09, "Pramod Immaneni"  wrote:
>
>> Bhupesh,
>>
>> Annotation seems like a static way to stop propagation. Give these are
>> programmatically generated I would think the operators should be able to
>> stop (consume without propagating) programmatically as well.
>>
>> Thanks
>>
>> On Thu, Dec 29, 2016 at 8:48 AM, Bhupesh Chawda 
>> wrote:
>>
>> > Thanks Vlad, I am trying out the approach you mentioned regarding having
>> > another interface which allows sinks to put a control tuple.
>> >
>> > Regarding the delivery of control tuples, here is what I am planning to
>> do:
>> > All the control tuples which are emitted in a particular window are
>> > delivered after all the data tuples have been delivered to the
>> respective
>> > ports, but before the endWindow() call. The operator can then process
>> the
>> > control tuples in that window and can do any finalization in the end
>> window
>> > call. There will be no delivery of control tuples after endWindow() and
>> > before the next beginWindow() call.
>> >
>> > For handling the propagation of control tuples further in the dag, we
>> are
>> > planning to have an annotation on the Output Port of the operator which
>> > would be true by default.
>> > @OutputPortFieldAnnotation(propogateControlTuples = false).
>> >
>> > ~ Bhupesh
>> >
>> >
>> > On Thu, Dec 29, 2016 at 6:24 AM, Vlad Rozov 
>> > wrote:
>> >
>> > > Custom control tuples are control tuples emitted by an operator itself
>> > and
>> > > not by the platform. Prior to the introduction of the custom control
>> > > tuples, only Apex engine itself puts control tuples into various
>> sinks,
>> > so
>> > > the engine created necessary Tuple objects with the corresponding type
>> > > prior to calling Sink.put().
>> > >
>> > > Not all sinks need to be changed. Only control tuple aware sinks
>> should
>> > > provide such functionality. In the case there is a lot of code
>> > duplication,
>> > > please create an abstract class, that other control aware sinks will
>> > extend
>> > > from.
>> > >
>> > > Thank you,
>> > >
>> > > Vlad
>> > >
>> > >
>> > > On 12/23/16 06:24, Bhupesh Chawda wrote:
>> > >
>> > >> Hi Vlad,
>> > >>
>> > >> Thanks for the pointer on delegating the wrapping of the user tuple
>> to
>> > the
>> > >> control port. I was trying this out today.
>> > >> The problem I see us if we introduce a putControlTuple() method in
>> Sink,
>> > >> then a lot of the existing sinks would change. Also the changes
>> seemed
>> > >> redundant as, the existing control tuples already use the put()
>> method
>> > of
>> > >> sinks. So why do something special for custom control tuples?
>> > >>
>> > >> The only aspect in which the custom control tuples are different is
>> that
>> > >> these will be generated by the user and will actually be delivered to
>> > the
>> > >> ports in a different order. Perhaps we should be able to use the
>> > existing
>> > >> flow. The only problems as outlined before seem to be identification
>> of
>> > >> the
>> > >> user tuple as a control tuple.
>> > >>
>> > >> ~ Bhupesh
>> > >>
>> > >>
>> > >> On Thu, Dec 22, 2016 at 10:44 PM, Vlad Rozov <
>> v.ro...@datatorrent.com>
>> > >> wrote:
>> > >>
>> > >> Why is it necessary to wrap in the OutputPort? Can't it be delegated
>> to
>> > a
>> > >>> Sink by introducing new putControlTuple method?
>> > >>>
>> > >>> Thank you,
>> > >>>
>> > >>> Vlad
>> > >>>
>> > >>>
>> > >>> On 12/21/16 22:10, Bhupesh Chawda wrote:
>> > >>>
>> > >>> Hi Vlad,
>> > 
>> >  The problem in using the Tuple class as the wrapper is that the
>> Ports
>> >  belong to the API and we want to wrap the payload object of the
>> > control
>> >  tuple into the Tuple class which is not part of the API.
>> > 
>> >  The output port will just get the payload of the user control
>> tuple.
>> > For
>> >  example, if the user emits a Long, as a control tuple, the payload
>> >  object
>> >  will just be a Long object.
>> > 
>> >  It is necessary to bundle this Long into some recognizable object
>> so
>> >  that
>> >  the BufferServerPublisher knows that this is a Control tuple and
>> not a
>> > 

Re: [DISCUSS] Custom Control Tuples Design

[Bhupesh Chawda]

Yes, that makes sense.
We have following options:
1. Make the annotation false by default and force the user to forward the
control tuples explicitly.
2. Annotation is true by default and static way of blocking stays as it is.
We provide another way for blocking programmatically, perhaps by means of
another method call on the port.

~ Bhupesh

On Dec 30, 2016 00:09, "Pramod Immaneni"  wrote:

> Bhupesh,
>
> Annotation seems like a static way to stop propagation. Give these are
> programmatically generated I would think the operators should be able to
> stop (consume without propagating) programmatically as well.
>
> Thanks
>
> On Thu, Dec 29, 2016 at 8:48 AM, Bhupesh Chawda 
> wrote:
>
> > Thanks Vlad, I am trying out the approach you mentioned regarding having
> > another interface which allows sinks to put a control tuple.
> >
> > Regarding the delivery of control tuples, here is what I am planning to
> do:
> > All the control tuples which are emitted in a particular window are
> > delivered after all the data tuples have been delivered to the respective
> > ports, but before the endWindow() call. The operator can then process the
> > control tuples in that window and can do any finalization in the end
> window
> > call. There will be no delivery of control tuples after endWindow() and
> > before the next beginWindow() call.
> >
> > For handling the propagation of control tuples further in the dag, we are
> > planning to have an annotation on the Output Port of the operator which
> > would be true by default.
> > @OutputPortFieldAnnotation(propogateControlTuples = false).
> >
> > ~ Bhupesh
> >
> >
> > On Thu, Dec 29, 2016 at 6:24 AM, Vlad Rozov 
> > wrote:
> >
> > > Custom control tuples are control tuples emitted by an operator itself
> > and
> > > not by the platform. Prior to the introduction of the custom control
> > > tuples, only Apex engine itself puts control tuples into various sinks,
> > so
> > > the engine created necessary Tuple objects with the corresponding type
> > > prior to calling Sink.put().
> > >
> > > Not all sinks need to be changed. Only control tuple aware sinks should
> > > provide such functionality. In the case there is a lot of code
> > duplication,
> > > please create an abstract class, that other control aware sinks will
> > extend
> > > from.
> > >
> > > Thank you,
> > >
> > > Vlad
> > >
> > >
> > > On 12/23/16 06:24, Bhupesh Chawda wrote:
> > >
> > >> Hi Vlad,
> > >>
> > >> Thanks for the pointer on delegating the wrapping of the user tuple to
> > the
> > >> control port. I was trying this out today.
> > >> The problem I see us if we introduce a putControlTuple() method in
> Sink,
> > >> then a lot of the existing sinks would change. Also the changes seemed
> > >> redundant as, the existing control tuples already use the put() method
> > of
> > >> sinks. So why do something special for custom control tuples?
> > >>
> > >> The only aspect in which the custom control tuples are different is
> that
> > >> these will be generated by the user and will actually be delivered to
> > the
> > >> ports in a different order. Perhaps we should be able to use the
> > existing
> > >> flow. The only problems as outlined before seem to be identification
> of
> > >> the
> > >> user tuple as a control tuple.
> > >>
> > >> ~ Bhupesh
> > >>
> > >>
> > >> On Thu, Dec 22, 2016 at 10:44 PM, Vlad Rozov  >
> > >> wrote:
> > >>
> > >> Why is it necessary to wrap in the OutputPort? Can't it be delegated
> to
> > a
> > >>> Sink by introducing new putControlTuple method?
> > >>>
> > >>> Thank you,
> > >>>
> > >>> Vlad
> > >>>
> > >>>
> > >>> On 12/21/16 22:10, Bhupesh Chawda wrote:
> > >>>
> > >>> Hi Vlad,
> > 
> >  The problem in using the Tuple class as the wrapper is that the
> Ports
> >  belong to the API and we want to wrap the payload object of the
> > control
> >  tuple into the Tuple class which is not part of the API.
> > 
> >  The output port will just get the payload of the user control tuple.
> > For
> >  example, if the user emits a Long, as a control tuple, the payload
> >  object
> >  will just be a Long object.
> > 
> >  It is necessary to bundle this Long into some recognizable object so
> >  that
> >  the BufferServerPublisher knows that this is a Control tuple and
> not a
> >  regular tuple and serialize it accordingly. It is therefore
> necessary
> >  that
> >  the tuple be part of some known hierarchy so that can be
> distinguished
> >  from
> >  other payload tuples. Let us call this class ControlTupleInterface.
> > Note
> >  that this needs to be done before the tuple is inserted into the
> sink
> >  which
> >  is done in the port objects. Once the tuple is inserted into the
> sink,
> >  it
> >  would seem just like any other payload tuple and cannot be
> >  distinguished.
> > 
> > 

Re: [DISCUSS] Custom Control Tuples Design

[Pramod Immaneni]

Bhupesh,

Annotation seems like a static way to stop propagation. Give these are
programmatically generated I would think the operators should be able to
stop (consume without propagating) programmatically as well.

Thanks

On Thu, Dec 29, 2016 at 8:48 AM, Bhupesh Chawda 
wrote:

> Thanks Vlad, I am trying out the approach you mentioned regarding having
> another interface which allows sinks to put a control tuple.
>
> Regarding the delivery of control tuples, here is what I am planning to do:
> All the control tuples which are emitted in a particular window are
> delivered after all the data tuples have been delivered to the respective
> ports, but before the endWindow() call. The operator can then process the
> control tuples in that window and can do any finalization in the end window
> call. There will be no delivery of control tuples after endWindow() and
> before the next beginWindow() call.
>
> For handling the propagation of control tuples further in the dag, we are
> planning to have an annotation on the Output Port of the operator which
> would be true by default.
> @OutputPortFieldAnnotation(propogateControlTuples = false).
>
> ~ Bhupesh
>
>
> On Thu, Dec 29, 2016 at 6:24 AM, Vlad Rozov 
> wrote:
>
> > Custom control tuples are control tuples emitted by an operator itself
> and
> > not by the platform. Prior to the introduction of the custom control
> > tuples, only Apex engine itself puts control tuples into various sinks,
> so
> > the engine created necessary Tuple objects with the corresponding type
> > prior to calling Sink.put().
> >
> > Not all sinks need to be changed. Only control tuple aware sinks should
> > provide such functionality. In the case there is a lot of code
> duplication,
> > please create an abstract class, that other control aware sinks will
> extend
> > from.
> >
> > Thank you,
> >
> > Vlad
> >
> >
> > On 12/23/16 06:24, Bhupesh Chawda wrote:
> >
> >> Hi Vlad,
> >>
> >> Thanks for the pointer on delegating the wrapping of the user tuple to
> the
> >> control port. I was trying this out today.
> >> The problem I see us if we introduce a putControlTuple() method in Sink,
> >> then a lot of the existing sinks would change. Also the changes seemed
> >> redundant as, the existing control tuples already use the put() method
> of
> >> sinks. So why do something special for custom control tuples?
> >>
> >> The only aspect in which the custom control tuples are different is that
> >> these will be generated by the user and will actually be delivered to
> the
> >> ports in a different order. Perhaps we should be able to use the
> existing
> >> flow. The only problems as outlined before seem to be identification of
> >> the
> >> user tuple as a control tuple.
> >>
> >> ~ Bhupesh
> >>
> >>
> >> On Thu, Dec 22, 2016 at 10:44 PM, Vlad Rozov 
> >> wrote:
> >>
> >> Why is it necessary to wrap in the OutputPort? Can't it be delegated to
> a
> >>> Sink by introducing new putControlTuple method?
> >>>
> >>> Thank you,
> >>>
> >>> Vlad
> >>>
> >>>
> >>> On 12/21/16 22:10, Bhupesh Chawda wrote:
> >>>
> >>> Hi Vlad,
> 
>  The problem in using the Tuple class as the wrapper is that the Ports
>  belong to the API and we want to wrap the payload object of the
> control
>  tuple into the Tuple class which is not part of the API.
> 
>  The output port will just get the payload of the user control tuple.
> For
>  example, if the user emits a Long, as a control tuple, the payload
>  object
>  will just be a Long object.
> 
>  It is necessary to bundle this Long into some recognizable object so
>  that
>  the BufferServerPublisher knows that this is a Control tuple and not a
>  regular tuple and serialize it accordingly. It is therefore necessary
>  that
>  the tuple be part of some known hierarchy so that can be distinguished
>  from
>  other payload tuples. Let us call this class ControlTupleInterface.
> Note
>  that this needs to be done before the tuple is inserted into the sink
>  which
>  is done in the port objects. Once the tuple is inserted into the sink,
>  it
>  would seem just like any other payload tuple and cannot be
>  distinguished.
> 
>  For this reason, I had something like the following in API:
> 
>  package com.datatorrent.api;
>  public class ControlTupleInterface
>  {
>  Object payload; // User control tuple payload. A Long() for
> example.
>  UUID id;  // Unique Id to de-duplicate in downstream operators
>  }
> 
>  Regarding your suggestion on using the Tuple class as the wrapper for
>  the
>  control tuple payload, let me mention the current scenario flow to
> make
>  the
>  discussion easier:
> 
>  We have a Tuple class in buffer server which is responsible for
>  serializing
>  the user control tuple bundling together a 

Re: [DISCUSS] Custom Control Tuples Design

[Bhupesh Chawda]

Thanks Vlad, I am trying out the approach you mentioned regarding having
another interface which allows sinks to put a control tuple.

Regarding the delivery of control tuples, here is what I am planning to do:
All the control tuples which are emitted in a particular window are
delivered after all the data tuples have been delivered to the respective
ports, but before the endWindow() call. The operator can then process the
control tuples in that window and can do any finalization in the end window
call. There will be no delivery of control tuples after endWindow() and
before the next beginWindow() call.

For handling the propagation of control tuples further in the dag, we are
planning to have an annotation on the Output Port of the operator which
would be true by default.
@OutputPortFieldAnnotation(propogateControlTuples = false).

~ Bhupesh


On Thu, Dec 29, 2016 at 6:24 AM, Vlad Rozov  wrote:

> Custom control tuples are control tuples emitted by an operator itself and
> not by the platform. Prior to the introduction of the custom control
> tuples, only Apex engine itself puts control tuples into various sinks, so
> the engine created necessary Tuple objects with the corresponding type
> prior to calling Sink.put().
>
> Not all sinks need to be changed. Only control tuple aware sinks should
> provide such functionality. In the case there is a lot of code duplication,
> please create an abstract class, that other control aware sinks will extend
> from.
>
> Thank you,
>
> Vlad
>
>
> On 12/23/16 06:24, Bhupesh Chawda wrote:
>
>> Hi Vlad,
>>
>> Thanks for the pointer on delegating the wrapping of the user tuple to the
>> control port. I was trying this out today.
>> The problem I see us if we introduce a putControlTuple() method in Sink,
>> then a lot of the existing sinks would change. Also the changes seemed
>> redundant as, the existing control tuples already use the put() method of
>> sinks. So why do something special for custom control tuples?
>>
>> The only aspect in which the custom control tuples are different is that
>> these will be generated by the user and will actually be delivered to the
>> ports in a different order. Perhaps we should be able to use the existing
>> flow. The only problems as outlined before seem to be identification of
>> the
>> user tuple as a control tuple.
>>
>> ~ Bhupesh
>>
>>
>> On Thu, Dec 22, 2016 at 10:44 PM, Vlad Rozov 
>> wrote:
>>
>> Why is it necessary to wrap in the OutputPort? Can't it be delegated to a
>>> Sink by introducing new putControlTuple method?
>>>
>>> Thank you,
>>>
>>> Vlad
>>>
>>>
>>> On 12/21/16 22:10, Bhupesh Chawda wrote:
>>>
>>> Hi Vlad,

 The problem in using the Tuple class as the wrapper is that the Ports
 belong to the API and we want to wrap the payload object of the control
 tuple into the Tuple class which is not part of the API.

 The output port will just get the payload of the user control tuple. For
 example, if the user emits a Long, as a control tuple, the payload
 object
 will just be a Long object.

 It is necessary to bundle this Long into some recognizable object so
 that
 the BufferServerPublisher knows that this is a Control tuple and not a
 regular tuple and serialize it accordingly. It is therefore necessary
 that
 the tuple be part of some known hierarchy so that can be distinguished
 from
 other payload tuples. Let us call this class ControlTupleInterface. Note
 that this needs to be done before the tuple is inserted into the sink
 which
 is done in the port objects. Once the tuple is inserted into the sink,
 it
 would seem just like any other payload tuple and cannot be
 distinguished.

 For this reason, I had something like the following in API:

 package com.datatorrent.api;
 public class ControlTupleInterface
 {
 Object payload; // User control tuple payload. A Long() for example.
 UUID id;  // Unique Id to de-duplicate in downstream operators
 }

 Regarding your suggestion on using the Tuple class as the wrapper for
 the
 control tuple payload, let me mention the current scenario flow to make
 the
 discussion easier:

 We have a Tuple class in buffer server which is responsible for
 serializing
 the user control tuple bundling together a message type:
 CUSTOM_CONTROL_TUPLE_VALUE.


 *com.datatorrent.bufferserver.packet.Tuple|--
 com.datatorrent.bufferserver.packet.CustomControlTuple*
 We have another Tuple class in Stram which helps the
 BufferServerSubscriber
 to de-serialize the serialized tuples. We should have CustomControlTuple
 in
 stram as follows:


 *com.datatorrent.stram.tuple.Tuple|--
 com.datatorrent.stram.tuple.CustomControlTuple*This will have a field
 for

 user control payload.

 I think we should 

Re: [DISCUSS] Custom Control Tuples Design

[Vlad Rozov]

Custom control tuples are control tuples emitted by an operator itself 
and not by the platform. Prior to the introduction of the custom control 
tuples, only Apex engine itself puts control tuples into various sinks, 
so the engine created necessary Tuple objects with the corresponding 
type prior to calling Sink.put().


Not all sinks need to be changed. Only control tuple aware sinks should 
provide such functionality. In the case there is a lot of code 
duplication, please create an abstract class, that other control aware 
sinks will extend from.


Thank you,

Vlad

On 12/23/16 06:24, Bhupesh Chawda wrote:

Hi Vlad,

Thanks for the pointer on delegating the wrapping of the user tuple to the
control port. I was trying this out today.
The problem I see us if we introduce a putControlTuple() method in Sink,
then a lot of the existing sinks would change. Also the changes seemed
redundant as, the existing control tuples already use the put() method of
sinks. So why do something special for custom control tuples?

The only aspect in which the custom control tuples are different is that
these will be generated by the user and will actually be delivered to the
ports in a different order. Perhaps we should be able to use the existing
flow. The only problems as outlined before seem to be identification of the
user tuple as a control tuple.

~ Bhupesh


On Thu, Dec 22, 2016 at 10:44 PM, Vlad Rozov 
wrote:


Why is it necessary to wrap in the OutputPort? Can't it be delegated to a
Sink by introducing new putControlTuple method?

Thank you,

Vlad


On 12/21/16 22:10, Bhupesh Chawda wrote:


Hi Vlad,

The problem in using the Tuple class as the wrapper is that the Ports
belong to the API and we want to wrap the payload object of the control
tuple into the Tuple class which is not part of the API.

The output port will just get the payload of the user control tuple. For
example, if the user emits a Long, as a control tuple, the payload object
will just be a Long object.

It is necessary to bundle this Long into some recognizable object so that
the BufferServerPublisher knows that this is a Control tuple and not a
regular tuple and serialize it accordingly. It is therefore necessary that
the tuple be part of some known hierarchy so that can be distinguished
from
other payload tuples. Let us call this class ControlTupleInterface. Note
that this needs to be done before the tuple is inserted into the sink
which
is done in the port objects. Once the tuple is inserted into the sink, it
would seem just like any other payload tuple and cannot be distinguished.

For this reason, I had something like the following in API:

package com.datatorrent.api;
public class ControlTupleInterface
{
Object payload; // User control tuple payload. A Long() for example.
UUID id;  // Unique Id to de-duplicate in downstream operators
}

Regarding your suggestion on using the Tuple class as the wrapper for the
control tuple payload, let me mention the current scenario flow to make
the
discussion easier:

We have a Tuple class in buffer server which is responsible for
serializing
the user control tuple bundling together a message type:
CUSTOM_CONTROL_TUPLE_VALUE.


*com.datatorrent.bufferserver.packet.Tuple|--
com.datatorrent.bufferserver.packet.CustomControlTuple*
We have another Tuple class in Stram which helps the
BufferServerSubscriber
to de-serialize the serialized tuples. We should have CustomControlTuple
in
stram as follows:


*com.datatorrent.stram.tuple.Tuple|--
com.datatorrent.stram.tuple.CustomControlTuple*This will have a field for

user control payload.

I think we should not expose the Tuple class in stram to the API. That was
the main reason I introduced another class/interface ControlTupleInterface
as described above.

Regarding, adding methods to DefaultInputPort and DefaultOutputPort, I
think error detection would not be early enough if the control tuple is
sent very late in the processing :-)
Extending the ports to ControlTupleAware* should help in this case.
However, we still need to see if there are any downsides on doing this.

Thanks.

~ Bhupesh




On Thu, Dec 22, 2016 at 7:26 AM, Vlad Rozov 
wrote:

Hi Bhupesh,

it should not be a CustomWrapper.  The wrapper object should be
CustomControlTuple that extends Tuple. There is already code that checks
for Tuple instance. The "unWrap" name is misleading, IMO. It should be
something like customControlTuple.getPayload() or
customControlTuple.getAttachment(). In the emitControl(), create new
CustomControlTuple using provided payload as one of arguments. It may
still
be good to use common parent other than Object for control tuple payload
class hierarchy.

I don't understand how adding more methods to the Default implementation
will help with early error detection unless application or operator that
relies on the custom control tuple functionality explicitly checks for
the
platform version at run-time or tries to emit a 

Re: [DISCUSS] Custom Control Tuples Design

[Bhupesh Chawda]

Hi Vlad,

Thanks for the pointer on delegating the wrapping of the user tuple to the
control port. I was trying this out today.
The problem I see us if we introduce a putControlTuple() method in Sink,
then a lot of the existing sinks would change. Also the changes seemed
redundant as, the existing control tuples already use the put() method of
sinks. So why do something special for custom control tuples?

The only aspect in which the custom control tuples are different is that
these will be generated by the user and will actually be delivered to the
ports in a different order. Perhaps we should be able to use the existing
flow. The only problems as outlined before seem to be identification of the
user tuple as a control tuple.

~ Bhupesh


On Thu, Dec 22, 2016 at 10:44 PM, Vlad Rozov 
wrote:

> Why is it necessary to wrap in the OutputPort? Can't it be delegated to a
> Sink by introducing new putControlTuple method?
>
> Thank you,
>
> Vlad
>
>
> On 12/21/16 22:10, Bhupesh Chawda wrote:
>
>> Hi Vlad,
>>
>> The problem in using the Tuple class as the wrapper is that the Ports
>> belong to the API and we want to wrap the payload object of the control
>> tuple into the Tuple class which is not part of the API.
>>
>> The output port will just get the payload of the user control tuple. For
>> example, if the user emits a Long, as a control tuple, the payload object
>> will just be a Long object.
>>
>> It is necessary to bundle this Long into some recognizable object so that
>> the BufferServerPublisher knows that this is a Control tuple and not a
>> regular tuple and serialize it accordingly. It is therefore necessary that
>> the tuple be part of some known hierarchy so that can be distinguished
>> from
>> other payload tuples. Let us call this class ControlTupleInterface. Note
>> that this needs to be done before the tuple is inserted into the sink
>> which
>> is done in the port objects. Once the tuple is inserted into the sink, it
>> would seem just like any other payload tuple and cannot be distinguished.
>>
>> For this reason, I had something like the following in API:
>>
>> package com.datatorrent.api;
>> public class ControlTupleInterface
>> {
>>Object payload; // User control tuple payload. A Long() for example.
>>UUID id;  // Unique Id to de-duplicate in downstream operators
>> }
>>
>> Regarding your suggestion on using the Tuple class as the wrapper for the
>> control tuple payload, let me mention the current scenario flow to make
>> the
>> discussion easier:
>>
>> We have a Tuple class in buffer server which is responsible for
>> serializing
>> the user control tuple bundling together a message type:
>> CUSTOM_CONTROL_TUPLE_VALUE.
>>
>>
>> *com.datatorrent.bufferserver.packet.Tuple|--
>> com.datatorrent.bufferserver.packet.CustomControlTuple*
>> We have another Tuple class in Stram which helps the
>> BufferServerSubscriber
>> to de-serialize the serialized tuples. We should have CustomControlTuple
>> in
>> stram as follows:
>>
>>
>> *com.datatorrent.stram.tuple.Tuple|--
>> com.datatorrent.stram.tuple.CustomControlTuple*This will have a field for
>>
>> user control payload.
>>
>> I think we should not expose the Tuple class in stram to the API. That was
>> the main reason I introduced another class/interface ControlTupleInterface
>> as described above.
>>
>> Regarding, adding methods to DefaultInputPort and DefaultOutputPort, I
>> think error detection would not be early enough if the control tuple is
>> sent very late in the processing :-)
>> Extending the ports to ControlTupleAware* should help in this case.
>> However, we still need to see if there are any downsides on doing this.
>>
>> Thanks.
>>
>> ~ Bhupesh
>>
>>
>>
>>
>> On Thu, Dec 22, 2016 at 7:26 AM, Vlad Rozov 
>> wrote:
>>
>> Hi Bhupesh,
>>>
>>> it should not be a CustomWrapper.  The wrapper object should be
>>> CustomControlTuple that extends Tuple. There is already code that checks
>>> for Tuple instance. The "unWrap" name is misleading, IMO. It should be
>>> something like customControlTuple.getPayload() or
>>> customControlTuple.getAttachment(). In the emitControl(), create new
>>> CustomControlTuple using provided payload as one of arguments. It may
>>> still
>>> be good to use common parent other than Object for control tuple payload
>>> class hierarchy.
>>>
>>> I don't understand how adding more methods to the Default implementation
>>> will help with early error detection unless application or operator that
>>> relies on the custom control tuple functionality explicitly checks for
>>> the
>>> platform version at run-time or tries to emit a control tuple just to
>>> check
>>> that such functionality is supported by the platform.
>>>
>>> Thank you,
>>>
>>> Vlad
>>>
>>> On 12/21/16 04:58, Bhupesh Chawda wrote:
>>>
>>> Hi Vlad.

 Yes, the API should not change. We can take an Object instead, and later
 wrap it into the required class.

 Our InputPort.put and 

Re: [DISCUSS] Custom Control Tuples Design

[Vlad Rozov]

Why is it necessary to wrap in the OutputPort? Can't it be delegated to 
a Sink by introducing new putControlTuple method?


Thank you,

Vlad

On 12/21/16 22:10, Bhupesh Chawda wrote:

Hi Vlad,

The problem in using the Tuple class as the wrapper is that the Ports
belong to the API and we want to wrap the payload object of the control
tuple into the Tuple class which is not part of the API.

The output port will just get the payload of the user control tuple. For
example, if the user emits a Long, as a control tuple, the payload object
will just be a Long object.

It is necessary to bundle this Long into some recognizable object so that
the BufferServerPublisher knows that this is a Control tuple and not a
regular tuple and serialize it accordingly. It is therefore necessary that
the tuple be part of some known hierarchy so that can be distinguished from
other payload tuples. Let us call this class ControlTupleInterface. Note
that this needs to be done before the tuple is inserted into the sink which
is done in the port objects. Once the tuple is inserted into the sink, it
would seem just like any other payload tuple and cannot be distinguished.

For this reason, I had something like the following in API:

package com.datatorrent.api;
public class ControlTupleInterface
{
   Object payload; // User control tuple payload. A Long() for example.
   UUID id;  // Unique Id to de-duplicate in downstream operators
}

Regarding your suggestion on using the Tuple class as the wrapper for the
control tuple payload, let me mention the current scenario flow to make the
discussion easier:

We have a Tuple class in buffer server which is responsible for serializing
the user control tuple bundling together a message type:
CUSTOM_CONTROL_TUPLE_VALUE.


*com.datatorrent.bufferserver.packet.Tuple|--
com.datatorrent.bufferserver.packet.CustomControlTuple*
We have another Tuple class in Stram which helps the BufferServerSubscriber
to de-serialize the serialized tuples. We should have CustomControlTuple in
stram as follows:


*com.datatorrent.stram.tuple.Tuple|--
com.datatorrent.stram.tuple.CustomControlTuple*This will have a field for
user control payload.

I think we should not expose the Tuple class in stram to the API. That was
the main reason I introduced another class/interface ControlTupleInterface
as described above.

Regarding, adding methods to DefaultInputPort and DefaultOutputPort, I
think error detection would not be early enough if the control tuple is
sent very late in the processing :-)
Extending the ports to ControlTupleAware* should help in this case.
However, we still need to see if there are any downsides on doing this.

Thanks.

~ Bhupesh




On Thu, Dec 22, 2016 at 7:26 AM, Vlad Rozov  wrote:


Hi Bhupesh,

it should not be a CustomWrapper.  The wrapper object should be
CustomControlTuple that extends Tuple. There is already code that checks
for Tuple instance. The "unWrap" name is misleading, IMO. It should be
something like customControlTuple.getPayload() or
customControlTuple.getAttachment(). In the emitControl(), create new
CustomControlTuple using provided payload as one of arguments. It may still
be good to use common parent other than Object for control tuple payload
class hierarchy.

I don't understand how adding more methods to the Default implementation
will help with early error detection unless application or operator that
relies on the custom control tuple functionality explicitly checks for the
platform version at run-time or tries to emit a control tuple just to check
that such functionality is supported by the platform.

Thank you,

Vlad

On 12/21/16 04:58, Bhupesh Chawda wrote:


Hi Vlad.

Yes, the API should not change. We can take an Object instead, and later
wrap it into the required class.

Our InputPort.put and emitControl method would look something like the
following where we handle the wrapping and unwrapping internally.

public void put(T tuple)
{
if (tuple instanceof CustomWrapper) {
  processControl(tuple.unWrap());
}  else {
  process(tuple)
}
}

emitControl(Object tuple)
{
sink.put(CustomWrapper.wrap(tuple));
}

Regarding the compatibility issue, I think we have two ways of doing it:

 1. Extend DefaultInputPort and DefaultOutputPort and create
 ControlAwareInput and ControlAwareOutput out of it. This might
require us
 to additionally handle specific cases when non-compatible ports
 (ControlAwareOutput and DefaultInput, for example) are connected to
each
 other in user apps.
 2. Add the additional methods in the existing Default implementations.


IMO, both of these would help in early error detection.

~ Bhupesh




On Wed, Dec 21, 2016 at 1:36 AM, Vlad Rozov 
wrote:

A wrapper class is required for the control tuples delivery, but

Port/Operator API should use Control Tuple payload object only.
Implementation of the wrapper class may change from version to version,
but
API 

Re: [DISCUSS] Custom Control Tuples Design

[Tushar Gosavi]

Hi Bhupesh,

We could have a marker interface with just one method getType() in
apex-api, our CustomControlTuple and stram Tuple will implement this
new interface.

interface ControlTuple {
  MessageType getType();
}

Add CUSTOM_TUPLE in MessageType enum and bring it in apex-api.

Our CustomControlTuple will implement ControlTuple with getType
returning CUSTOM_TUPLE, and Tuple in stram will implement ControlTuple
in api with getType return type.

Regards,
- Tushar.

On Thu, Dec 22, 2016 at 12:12 PM, Bhupesh Chawda
 wrote:
> There is another issue with the current approach which fails in case tuples
> skip serialization. To address this, we have the following options:
>
> One of the options, is that we have a common class in API which is the
> parent for both Tuple class in Stram and also the parent of the custom
> control tuple payload. This can help us treat the control tuple payload as
> a Tuple.
> However, this might require us to move some things like MessageType into
> api as well. And would also need a lot of refactorings in the existing
> Reservoir code.
>
> Another option is to specially handle the case of CustomControlTuple in all
> the Reservoir sweep() methods where we check for not only a Tuple class,
> but also for the user control tuple payload class and return it once we
> encounter it, thus identifying the user custom payload as a control tuple.
>
> Thoughts?
>
> ~ Bhupesh
>
>
>
>
>
> On Thu, Dec 22, 2016 at 11:40 AM, Bhupesh Chawda 
> wrote:
>
>> Hi Vlad,
>>
>> The problem in using the Tuple class as the wrapper is that the Ports
>> belong to the API and we want to wrap the payload object of the control
>> tuple into the Tuple class which is not part of the API.
>>
>> The output port will just get the payload of the user control tuple. For
>> example, if the user emits a Long, as a control tuple, the payload object
>> will just be a Long object.
>>
>> It is necessary to bundle this Long into some recognizable object so that
>> the BufferServerPublisher knows that this is a Control tuple and not a
>> regular tuple and serialize it accordingly. It is therefore necessary that
>> the tuple be part of some known hierarchy so that can be distinguished from
>> other payload tuples. Let us call this class ControlTupleInterface. Note
>> that this needs to be done before the tuple is inserted into the sink which
>> is done in the port objects. Once the tuple is inserted into the sink, it
>> would seem just like any other payload tuple and cannot be distinguished.
>>
>> For this reason, I had something like the following in API:
>>
>> package com.datatorrent.api;
>> public class ControlTupleInterface
>> {
>>   Object payload; // User control tuple payload. A Long() for example.
>>   UUID id;  // Unique Id to de-duplicate in downstream operators
>> }
>>
>> Regarding your suggestion on using the Tuple class as the wrapper for the
>> control tuple payload, let me mention the current scenario flow to make the
>> discussion easier:
>>
>> We have a Tuple class in buffer server which is responsible for
>> serializing the user control tuple bundling together a message type:
>> CUSTOM_CONTROL_TUPLE_VALUE.
>>
>>
>> *com.datatorrent.bufferserver.packet.Tuple|--
>> com.datatorrent.bufferserver.packet.CustomControlTuple*
>> We have another Tuple class in Stram which helps the
>> BufferServerSubscriber to de-serialize the serialized tuples. We should
>> have CustomControlTuple in stram as follows:
>>
>>
>> *com.datatorrent.stram.tuple.Tuple|--
>> com.datatorrent.stram.tuple.CustomControlTuple*This will have a field for
>> user control payload.
>>
>> I think we should not expose the Tuple class in stram to the API. That was
>> the main reason I introduced another class/interface ControlTupleInterface
>> as described above.
>>
>> Regarding, adding methods to DefaultInputPort and DefaultOutputPort, I
>> think error detection would not be early enough if the control tuple is
>> sent very late in the processing :-)
>> Extending the ports to ControlTupleAware* should help in this case.
>> However, we still need to see if there are any downsides on doing this.
>>
>> Thanks.
>>
>> ~ Bhupesh
>>
>>
>>
>>
>> On Thu, Dec 22, 2016 at 7:26 AM, Vlad Rozov 
>> wrote:
>>
>>> Hi Bhupesh,
>>>
>>> it should not be a CustomWrapper.  The wrapper object should be
>>> CustomControlTuple that extends Tuple. There is already code that checks
>>> for Tuple instance. The "unWrap" name is misleading, IMO. It should be
>>> something like customControlTuple.getPayload() or
>>> customControlTuple.getAttachment(). In the emitControl(), create new
>>> CustomControlTuple using provided payload as one of arguments. It may still
>>> be good to use common parent other than Object for control tuple payload
>>> class hierarchy.
>>>
>>> I don't understand how adding more methods to the Default implementation
>>> will help with early error detection unless application or operator 

Re: [DISCUSS] Custom Control Tuples Design

[Bhupesh Chawda]

There is another issue with the current approach which fails in case tuples
skip serialization. To address this, we have the following options:

One of the options, is that we have a common class in API which is the
parent for both Tuple class in Stram and also the parent of the custom
control tuple payload. This can help us treat the control tuple payload as
a Tuple.
However, this might require us to move some things like MessageType into
api as well. And would also need a lot of refactorings in the existing
Reservoir code.

Another option is to specially handle the case of CustomControlTuple in all
the Reservoir sweep() methods where we check for not only a Tuple class,
but also for the user control tuple payload class and return it once we
encounter it, thus identifying the user custom payload as a control tuple.

Thoughts?

~ Bhupesh





On Thu, Dec 22, 2016 at 11:40 AM, Bhupesh Chawda 
wrote:

> Hi Vlad,
>
> The problem in using the Tuple class as the wrapper is that the Ports
> belong to the API and we want to wrap the payload object of the control
> tuple into the Tuple class which is not part of the API.
>
> The output port will just get the payload of the user control tuple. For
> example, if the user emits a Long, as a control tuple, the payload object
> will just be a Long object.
>
> It is necessary to bundle this Long into some recognizable object so that
> the BufferServerPublisher knows that this is a Control tuple and not a
> regular tuple and serialize it accordingly. It is therefore necessary that
> the tuple be part of some known hierarchy so that can be distinguished from
> other payload tuples. Let us call this class ControlTupleInterface. Note
> that this needs to be done before the tuple is inserted into the sink which
> is done in the port objects. Once the tuple is inserted into the sink, it
> would seem just like any other payload tuple and cannot be distinguished.
>
> For this reason, I had something like the following in API:
>
> package com.datatorrent.api;
> public class ControlTupleInterface
> {
>   Object payload; // User control tuple payload. A Long() for example.
>   UUID id;  // Unique Id to de-duplicate in downstream operators
> }
>
> Regarding your suggestion on using the Tuple class as the wrapper for the
> control tuple payload, let me mention the current scenario flow to make the
> discussion easier:
>
> We have a Tuple class in buffer server which is responsible for
> serializing the user control tuple bundling together a message type:
> CUSTOM_CONTROL_TUPLE_VALUE.
>
>
> *com.datatorrent.bufferserver.packet.Tuple|--
> com.datatorrent.bufferserver.packet.CustomControlTuple*
> We have another Tuple class in Stram which helps the
> BufferServerSubscriber to de-serialize the serialized tuples. We should
> have CustomControlTuple in stram as follows:
>
>
> *com.datatorrent.stram.tuple.Tuple|--
> com.datatorrent.stram.tuple.CustomControlTuple*This will have a field for
> user control payload.
>
> I think we should not expose the Tuple class in stram to the API. That was
> the main reason I introduced another class/interface ControlTupleInterface
> as described above.
>
> Regarding, adding methods to DefaultInputPort and DefaultOutputPort, I
> think error detection would not be early enough if the control tuple is
> sent very late in the processing :-)
> Extending the ports to ControlTupleAware* should help in this case.
> However, we still need to see if there are any downsides on doing this.
>
> Thanks.
>
> ~ Bhupesh
>
>
>
>
> On Thu, Dec 22, 2016 at 7:26 AM, Vlad Rozov 
> wrote:
>
>> Hi Bhupesh,
>>
>> it should not be a CustomWrapper.  The wrapper object should be
>> CustomControlTuple that extends Tuple. There is already code that checks
>> for Tuple instance. The "unWrap" name is misleading, IMO. It should be
>> something like customControlTuple.getPayload() or
>> customControlTuple.getAttachment(). In the emitControl(), create new
>> CustomControlTuple using provided payload as one of arguments. It may still
>> be good to use common parent other than Object for control tuple payload
>> class hierarchy.
>>
>> I don't understand how adding more methods to the Default implementation
>> will help with early error detection unless application or operator that
>> relies on the custom control tuple functionality explicitly checks for the
>> platform version at run-time or tries to emit a control tuple just to check
>> that such functionality is supported by the platform.
>>
>> Thank you,
>>
>> Vlad
>>
>> On 12/21/16 04:58, Bhupesh Chawda wrote:
>>
>>> Hi Vlad.
>>>
>>> Yes, the API should not change. We can take an Object instead, and later
>>> wrap it into the required class.
>>>
>>> Our InputPort.put and emitControl method would look something like the
>>> following where we handle the wrapping and unwrapping internally.
>>>
>>> public void put(T tuple)
>>> {
>>>if (tuple instanceof CustomWrapper) {
>>>  

Re: [DISCUSS] Custom Control Tuples Design

[Bhupesh Chawda]

Hi Vlad,

The problem in using the Tuple class as the wrapper is that the Ports
belong to the API and we want to wrap the payload object of the control
tuple into the Tuple class which is not part of the API.

The output port will just get the payload of the user control tuple. For
example, if the user emits a Long, as a control tuple, the payload object
will just be a Long object.

It is necessary to bundle this Long into some recognizable object so that
the BufferServerPublisher knows that this is a Control tuple and not a
regular tuple and serialize it accordingly. It is therefore necessary that
the tuple be part of some known hierarchy so that can be distinguished from
other payload tuples. Let us call this class ControlTupleInterface. Note
that this needs to be done before the tuple is inserted into the sink which
is done in the port objects. Once the tuple is inserted into the sink, it
would seem just like any other payload tuple and cannot be distinguished.

For this reason, I had something like the following in API:

package com.datatorrent.api;
public class ControlTupleInterface
{
  Object payload; // User control tuple payload. A Long() for example.
  UUID id;  // Unique Id to de-duplicate in downstream operators
}

Regarding your suggestion on using the Tuple class as the wrapper for the
control tuple payload, let me mention the current scenario flow to make the
discussion easier:

We have a Tuple class in buffer server which is responsible for serializing
the user control tuple bundling together a message type:
CUSTOM_CONTROL_TUPLE_VALUE.


*com.datatorrent.bufferserver.packet.Tuple|--
com.datatorrent.bufferserver.packet.CustomControlTuple*
We have another Tuple class in Stram which helps the BufferServerSubscriber
to de-serialize the serialized tuples. We should have CustomControlTuple in
stram as follows:


*com.datatorrent.stram.tuple.Tuple|--
com.datatorrent.stram.tuple.CustomControlTuple*This will have a field for
user control payload.

I think we should not expose the Tuple class in stram to the API. That was
the main reason I introduced another class/interface ControlTupleInterface
as described above.

Regarding, adding methods to DefaultInputPort and DefaultOutputPort, I
think error detection would not be early enough if the control tuple is
sent very late in the processing :-)
Extending the ports to ControlTupleAware* should help in this case.
However, we still need to see if there are any downsides on doing this.

Thanks.

~ Bhupesh




On Thu, Dec 22, 2016 at 7:26 AM, Vlad Rozov  wrote:

> Hi Bhupesh,
>
> it should not be a CustomWrapper.  The wrapper object should be
> CustomControlTuple that extends Tuple. There is already code that checks
> for Tuple instance. The "unWrap" name is misleading, IMO. It should be
> something like customControlTuple.getPayload() or
> customControlTuple.getAttachment(). In the emitControl(), create new
> CustomControlTuple using provided payload as one of arguments. It may still
> be good to use common parent other than Object for control tuple payload
> class hierarchy.
>
> I don't understand how adding more methods to the Default implementation
> will help with early error detection unless application or operator that
> relies on the custom control tuple functionality explicitly checks for the
> platform version at run-time or tries to emit a control tuple just to check
> that such functionality is supported by the platform.
>
> Thank you,
>
> Vlad
>
> On 12/21/16 04:58, Bhupesh Chawda wrote:
>
>> Hi Vlad.
>>
>> Yes, the API should not change. We can take an Object instead, and later
>> wrap it into the required class.
>>
>> Our InputPort.put and emitControl method would look something like the
>> following where we handle the wrapping and unwrapping internally.
>>
>> public void put(T tuple)
>> {
>>if (tuple instanceof CustomWrapper) {
>>  processControl(tuple.unWrap());
>>}  else {
>>  process(tuple)
>>}
>> }
>>
>> emitControl(Object tuple)
>> {
>>sink.put(CustomWrapper.wrap(tuple));
>> }
>>
>> Regarding the compatibility issue, I think we have two ways of doing it:
>>
>> 1. Extend DefaultInputPort and DefaultOutputPort and create
>> ControlAwareInput and ControlAwareOutput out of it. This might
>> require us
>> to additionally handle specific cases when non-compatible ports
>> (ControlAwareOutput and DefaultInput, for example) are connected to
>> each
>> other in user apps.
>> 2. Add the additional methods in the existing Default implementations.
>>
>>
>> IMO, both of these would help in early error detection.
>>
>> ~ Bhupesh
>>
>>
>>
>>
>> On Wed, Dec 21, 2016 at 1:36 AM, Vlad Rozov 
>> wrote:
>>
>> A wrapper class is required for the control tuples delivery, but
>>> Port/Operator API should use Control Tuple payload object only.
>>> Implementation of the wrapper class may change from version to version,
>>> but
>>> API should not be affected by the 

Re: [DISCUSS] Custom Control Tuples Design

[Vlad Rozov]

Hi Bhupesh,

it should not be a CustomWrapper.  The wrapper object should be 
CustomControlTuple that extends Tuple. There is already code that checks 
for Tuple instance. The "unWrap" name is misleading, IMO. It should be 
something like customControlTuple.getPayload() or 
customControlTuple.getAttachment(). In the emitControl(), create new 
CustomControlTuple using provided payload as one of arguments. It may 
still be good to use common parent other than Object for control tuple 
payload class hierarchy.


I don't understand how adding more methods to the Default implementation 
will help with early error detection unless application or operator that 
relies on the custom control tuple functionality explicitly checks for 
the platform version at run-time or tries to emit a control tuple just 
to check that such functionality is supported by the platform.


Thank you,

Vlad

On 12/21/16 04:58, Bhupesh Chawda wrote:

Hi Vlad.

Yes, the API should not change. We can take an Object instead, and later
wrap it into the required class.

Our InputPort.put and emitControl method would look something like the
following where we handle the wrapping and unwrapping internally.

public void put(T tuple)
{
   if (tuple instanceof CustomWrapper) {
 processControl(tuple.unWrap());
   }  else {
 process(tuple)
   }
}

emitControl(Object tuple)
{
   sink.put(CustomWrapper.wrap(tuple));
}

Regarding the compatibility issue, I think we have two ways of doing it:

1. Extend DefaultInputPort and DefaultOutputPort and create
ControlAwareInput and ControlAwareOutput out of it. This might require us
to additionally handle specific cases when non-compatible ports
(ControlAwareOutput and DefaultInput, for example) are connected to each
other in user apps.
2. Add the additional methods in the existing Default implementations.

IMO, both of these would help in early error detection.

~ Bhupesh




On Wed, Dec 21, 2016 at 1:36 AM, Vlad Rozov  wrote:


A wrapper class is required for the control tuples delivery, but
Port/Operator API should use Control Tuple payload object only.
Implementation of the wrapper class may change from version to version, but
API should not be affected by the change.

I guess, assumption is that default input and output port will be extended
to provide support for the control tuples. This may cause some backward
compatibility issues. Consider scenario when a newer version of Malhar that
relies on EOF control tuple is deployed into older version of core that
does not support control tuples. In such scenario, error will be raised
only when an operator tries to emit EOF control tuple at the end of a job.
Introducing control tuple aware ports solve the early error detection. It
will require some operators to be modified to use control tuple aware
ports, but such change may help to distinguish control tuple aware
operators from their old versions.

Vlad

On 12/20/16 04:09, Bhupesh Chawda wrote:


I investigated this and seems like it is better to have a wrapper class
for
the user object.
This would serve 2 purposes:

 1. Allow us to distinguish a custom control tuple from other payload
 tuples.
 2. For the same control tuple received from different upstream

 partitions, we would have some mechanism to distinguish between the
two in
 order to identify duplicates.

Additionally, the wrapper class needs to be part of the API as
DefaultOutputPort needs to know about it, before putting it into the sink.
We can make sure that the user is not able to extend or modify this class
in any manner.

~ Bhupesh

On Mon, Dec 19, 2016 at 12:18 PM, David Yan  wrote:

This C type parameter is going to fix the control tuple type at compile

time and this is actually not what we want. Note that the operator may
receive or emit multiple different control tuple types.

David

On Dec 17, 2016 3:33 AM, "Tushar Gosavi"  wrote:

We do not need to create an interface for data emitted through
emitControl or processed through processControl. Internally we could
wrap the user object in ControlTuple. you can add type parameter for
control tuple object on ports.

DefaultInputPort
D is the data type and C is the control tuple type for better error
catching at compile phase.


- Tushar.


On Sat, Dec 17, 2016 at 8:35 AM, Bhupesh Chawda 


wrote:


I agree with David. Payload of the control tuple is in the userObject
and

Re: [DISCUSS] Custom Control Tuples Design

[Bhupesh Chawda]

Hi Vlad.

Yes, the API should not change. We can take an Object instead, and later
wrap it into the required class.

Our InputPort.put and emitControl method would look something like the
following where we handle the wrapping and unwrapping internally.

public void put(T tuple)
{
  if (tuple instanceof CustomWrapper) {
processControl(tuple.unWrap());
  }  else {
process(tuple)
  }
}

emitControl(Object tuple)
{
  sink.put(CustomWrapper.wrap(tuple));
}

Regarding the compatibility issue, I think we have two ways of doing it:

   1. Extend DefaultInputPort and DefaultOutputPort and create
   ControlAwareInput and ControlAwareOutput out of it. This might require us
   to additionally handle specific cases when non-compatible ports
   (ControlAwareOutput and DefaultInput, for example) are connected to each
   other in user apps.
   2. Add the additional methods in the existing Default implementations.

IMO, both of these would help in early error detection.

~ Bhupesh




On Wed, Dec 21, 2016 at 1:36 AM, Vlad Rozov  wrote:

> A wrapper class is required for the control tuples delivery, but
> Port/Operator API should use Control Tuple payload object only.
> Implementation of the wrapper class may change from version to version, but
> API should not be affected by the change.
>
> I guess, assumption is that default input and output port will be extended
> to provide support for the control tuples. This may cause some backward
> compatibility issues. Consider scenario when a newer version of Malhar that
> relies on EOF control tuple is deployed into older version of core that
> does not support control tuples. In such scenario, error will be raised
> only when an operator tries to emit EOF control tuple at the end of a job.
> Introducing control tuple aware ports solve the early error detection. It
> will require some operators to be modified to use control tuple aware
> ports, but such change may help to distinguish control tuple aware
> operators from their old versions.
>
> Vlad
>
> On 12/20/16 04:09, Bhupesh Chawda wrote:
>
>> I investigated this and seems like it is better to have a wrapper class
>> for
>> the user object.
>> This would serve 2 purposes:
>>
>> 1. Allow us to distinguish a custom control tuple from other payload
>> tuples.
>> 2. For the same control tuple received from different upstream
>>
>> partitions, we would have some mechanism to distinguish between the
>> two in
>> order to identify duplicates.
>>
>> Additionally, the wrapper class needs to be part of the API as
>> DefaultOutputPort needs to know about it, before putting it into the sink.
>> We can make sure that the user is not able to extend or modify this class
>> in any manner.
>>
>> ~ Bhupesh
>>
>> On Mon, Dec 19, 2016 at 12:18 PM, David Yan  wrote:
>>
>> This C type parameter is going to fix the control tuple type at compile
>>> time and this is actually not what we want. Note that the operator may
>>> receive or emit multiple different control tuple types.
>>>
>>> David
>>>
>>> On Dec 17, 2016 3:33 AM, "Tushar Gosavi"  wrote:
>>>
>>> We do not need to create an interface for data emitted through
>>> emitControl or processed through processControl. Internally we could
>>> wrap the user object in ControlTuple. you can add type parameter for
>>> control tuple object on ports.
>>>
>>> DefaultInputPort
>>> D is the data type and C is the control tuple type for better error
>>> catching at compile phase.
>>>
>>>
>>> - Tushar.
>>>
>>>
>>> On Sat, Dec 17, 2016 at 8:35 AM, Bhupesh Chawda >> >
>>> wrote:
>>>
 Agreed Vlad and David.
 I am just suggesting there should be a wrapper for the user object. It

>>> can
>>>
 be a marker interface and we can call it something else like
 "CustomControl".

 The user object will be wrapped in another class "ControlTuple" which
 traverses the BufferServer and will perhaps be extended from the
 packet/Tuple class. This class will not be exposed to the user.

 ~ Bhupesh


 On Sat, Dec 17, 2016 at 4:11 AM, Vlad Rozov 

>>> wrote:
>>>
 I agree with David. Payload of the control tuple is in the userObject
>
 and
>>>
 operators/ports don't need to be exposed to the implementation of the
> ControlTuple class. With the proposed interface operators developers
> are
> free to extend ControlTuple further and I don't think that such
>
 capability
>>>
 needs to be provided. The wrapping in the ControlTuple class is
>
 necessary
>>>
 and most likely ControlTuple needs to be extended from the buffer server
> Tuple. It may be good to have a common parent other than Object for all
> user payloads, but it may be a marker interface as well.
>
> Thank you,
>
> Vlad
>
>
> On 12/16/16 09:59, Bhupesh Chawda wrote:
>
> 

Re: [DISCUSS] Custom Control Tuples Design

[Vlad Rozov]

A wrapper class is required for the control tuples delivery, but 
Port/Operator API should use Control Tuple payload object only. 
Implementation of the wrapper class may change from version to version, 
but API should not be affected by the change.


I guess, assumption is that default input and output port will be 
extended to provide support for the control tuples. This may cause some 
backward compatibility issues. Consider scenario when a newer version of 
Malhar that relies on EOF control tuple is deployed into older version 
of core that does not support control tuples. In such scenario, error 
will be raised only when an operator tries to emit EOF control tuple at 
the end of a job. Introducing control tuple aware ports solve the early 
error detection. It will require some operators to be modified to use 
control tuple aware ports, but such change may help to distinguish 
control tuple aware operators from their old versions.


Vlad

On 12/20/16 04:09, Bhupesh Chawda wrote:

I investigated this and seems like it is better to have a wrapper class for
the user object.
This would serve 2 purposes:

1. Allow us to distinguish a custom control tuple from other payload
tuples.
2. For the same control tuple received from different upstream
partitions, we would have some mechanism to distinguish between the two in
order to identify duplicates.

Additionally, the wrapper class needs to be part of the API as
DefaultOutputPort needs to know about it, before putting it into the sink.
We can make sure that the user is not able to extend or modify this class
in any manner.

~ Bhupesh

On Mon, Dec 19, 2016 at 12:18 PM, David Yan  wrote:


This C type parameter is going to fix the control tuple type at compile
time and this is actually not what we want. Note that the operator may
receive or emit multiple different control tuple types.

David

On Dec 17, 2016 3:33 AM, "Tushar Gosavi"  wrote:

We do not need to create an interface for data emitted through
emitControl or processed through processControl. Internally we could
wrap the user object in ControlTuple. you can add type parameter for
control tuple object on ports.

DefaultInputPort
D is the data type and C is the control tuple type for better error
catching at compile phase.


- Tushar.


On Sat, Dec 17, 2016 at 8:35 AM, Bhupesh Chawda 
wrote:

Agreed Vlad and David.
I am just suggesting there should be a wrapper for the user object. It

can

be a marker interface and we can call it something else like
"CustomControl".

The user object will be wrapped in another class "ControlTuple" which
traverses the BufferServer and will perhaps be extended from the
packet/Tuple class. This class will not be exposed to the user.

~ Bhupesh


On Sat, Dec 17, 2016 at 4:11 AM, Vlad Rozov 

wrote:

I agree with David. Payload of the control tuple is in the userObject

and

operators/ports don't need to be exposed to the implementation of the
ControlTuple class. With the proposed interface operators developers are
free to extend ControlTuple further and I don't think that such

capability

needs to be provided. The wrapping in the ControlTuple class is

necessary

and most likely ControlTuple needs to be extended from the buffer server
Tuple. It may be good to have a common parent other than Object for all
user payloads, but it may be a marker interface as well.

Thank you,

Vlad


On 12/16/16 09:59, Bhupesh Chawda wrote:


Hi David,

Actually, I was thinking of another API class called ControlTuple,
different from the actual tuple class in buffer server or stram.
This could serve as a way for the Buffer server publisher to understand
that it is a control tuple and needs to be wrapped differently.

~ Bhupesh



On Dec 16, 2016 22:28, "David Yan"  wrote:

   // DefaultInputPort
public void processControl(ControlTuple tuple)
{
  // Default Implementation to avoid need to implement it in all
implementations
}
{code}

{code}
   // DefaultOutputPort
public void emitControl(ControlTuple tuple)
{
}

I think we don't need to expose the ControlTuple class to the operator
developers because the window ID is just the current window ID when

these

methods are called. How about making them just Object? We also need to
provide the way for the user to specify custom serializer for the

control

tuple.

David


On Thu, Dec 15, 2016 at 12:43 AM, Bhupesh Chawda <

bhup...@datatorrent.com

wrote:

Hi All,

Here are the initial interfaces:

{code}
   // DefaultInputPort
public void processControl(ControlTuple tuple)
{
  // Default Implementation to avoid need to implement it in all
implementations
}
{code}

{code}
   // DefaultOutputPort
public void emitControl(ControlTuple tuple)
{
}
{code}

We have an option to add these methods to the interfaces - InputPort

and

OutputPort; But these would not be 

Re: [DISCUSS] Custom Control Tuples Design

[Bhupesh Chawda]

I investigated this and seems like it is better to have a wrapper class for
the user object.
This would serve 2 purposes:

   1. Allow us to distinguish a custom control tuple from other payload
   tuples.
   2. For the same control tuple received from different upstream
   partitions, we would have some mechanism to distinguish between the two in
   order to identify duplicates.

Additionally, the wrapper class needs to be part of the API as
DefaultOutputPort needs to know about it, before putting it into the sink.
We can make sure that the user is not able to extend or modify this class
in any manner.

~ Bhupesh

On Mon, Dec 19, 2016 at 12:18 PM, David Yan  wrote:

> This C type parameter is going to fix the control tuple type at compile
> time and this is actually not what we want. Note that the operator may
> receive or emit multiple different control tuple types.
>
> David
>
> On Dec 17, 2016 3:33 AM, "Tushar Gosavi"  wrote:
>
> We do not need to create an interface for data emitted through
> emitControl or processed through processControl. Internally we could
> wrap the user object in ControlTuple. you can add type parameter for
> control tuple object on ports.
>
> DefaultInputPort
> D is the data type and C is the control tuple type for better error
> catching at compile phase.
>
>
> - Tushar.
>
>
> On Sat, Dec 17, 2016 at 8:35 AM, Bhupesh Chawda 
> wrote:
> > Agreed Vlad and David.
> > I am just suggesting there should be a wrapper for the user object. It
> can
> > be a marker interface and we can call it something else like
> > "CustomControl".
> >
> > The user object will be wrapped in another class "ControlTuple" which
> > traverses the BufferServer and will perhaps be extended from the
> > packet/Tuple class. This class will not be exposed to the user.
> >
> > ~ Bhupesh
> >
> >
> > On Sat, Dec 17, 2016 at 4:11 AM, Vlad Rozov 
> wrote:
> >
> >> I agree with David. Payload of the control tuple is in the userObject
> and
> >> operators/ports don't need to be exposed to the implementation of the
> >> ControlTuple class. With the proposed interface operators developers are
> >> free to extend ControlTuple further and I don't think that such
> capability
> >> needs to be provided. The wrapping in the ControlTuple class is
> necessary
> >> and most likely ControlTuple needs to be extended from the buffer server
> >> Tuple. It may be good to have a common parent other than Object for all
> >> user payloads, but it may be a marker interface as well.
> >>
> >> Thank you,
> >>
> >> Vlad
> >>
> >>
> >> On 12/16/16 09:59, Bhupesh Chawda wrote:
> >>
> >>> Hi David,
> >>>
> >>> Actually, I was thinking of another API class called ControlTuple,
> >>> different from the actual tuple class in buffer server or stram.
> >>> This could serve as a way for the Buffer server publisher to understand
> >>> that it is a control tuple and needs to be wrapped differently.
> >>>
> >>> ~ Bhupesh
> >>>
> >>>
> >>>
> >>> On Dec 16, 2016 22:28, "David Yan"  wrote:
> >>>
> >>>   // DefaultInputPort
> >>>public void processControl(ControlTuple tuple)
> >>>{
> >>>  // Default Implementation to avoid need to implement it in all
> >>> implementations
> >>>}
> >>> {code}
> >>>
> >>> {code}
> >>>   // DefaultOutputPort
> >>>public void emitControl(ControlTuple tuple)
> >>>{
> >>>}
> >>>
> >>> I think we don't need to expose the ControlTuple class to the operator
> >>> developers because the window ID is just the current window ID when
> these
> >>> methods are called. How about making them just Object? We also need to
> >>> provide the way for the user to specify custom serializer for the
> control
> >>> tuple.
> >>>
> >>> David
> >>>
> >>>
> >>> On Thu, Dec 15, 2016 at 12:43 AM, Bhupesh Chawda <
> bhup...@datatorrent.com
> >>> >
> >>> wrote:
> >>>
> >>> Hi All,
> 
>  Here are the initial interfaces:
> 
>  {code}
>    // DefaultInputPort
> public void processControl(ControlTuple tuple)
> {
>   // Default Implementation to avoid need to implement it in all
>  implementations
> }
>  {code}
> 
>  {code}
>    // DefaultOutputPort
> public void emitControl(ControlTuple tuple)
> {
> }
>  {code}
> 
>  We have an option to add these methods to the interfaces - InputPort
> and
>  OutputPort; But these would not be backward compatible and also not
>  consistent with the current implementation of basic data tuple flow
> (as
>  with process() and emit()).
> 
>  We also need to expose an interface / class for users to wrap their
>  object
>  and emit downstream. This should be part of API.
> 
>  {code}
>  public class ControlTuple extends Tuple
>  {
> Object userObject;
> 
> public ControlTuple(long windowId, Object userObject)
> 

Re: [DISCUSS] Custom Control Tuples Design

[David Yan]

This C type parameter is going to fix the control tuple type at compile
time and this is actually not what we want. Note that the operator may
receive or emit multiple different control tuple types.

David

On Dec 17, 2016 3:33 AM, "Tushar Gosavi"  wrote:

We do not need to create an interface for data emitted through
emitControl or processed through processControl. Internally we could
wrap the user object in ControlTuple. you can add type parameter for
control tuple object on ports.

DefaultInputPort
D is the data type and C is the control tuple type for better error
catching at compile phase.


- Tushar.


On Sat, Dec 17, 2016 at 8:35 AM, Bhupesh Chawda 
wrote:
> Agreed Vlad and David.
> I am just suggesting there should be a wrapper for the user object. It can
> be a marker interface and we can call it something else like
> "CustomControl".
>
> The user object will be wrapped in another class "ControlTuple" which
> traverses the BufferServer and will perhaps be extended from the
> packet/Tuple class. This class will not be exposed to the user.
>
> ~ Bhupesh
>
>
> On Sat, Dec 17, 2016 at 4:11 AM, Vlad Rozov 
wrote:
>
>> I agree with David. Payload of the control tuple is in the userObject and
>> operators/ports don't need to be exposed to the implementation of the
>> ControlTuple class. With the proposed interface operators developers are
>> free to extend ControlTuple further and I don't think that such
capability
>> needs to be provided. The wrapping in the ControlTuple class is necessary
>> and most likely ControlTuple needs to be extended from the buffer server
>> Tuple. It may be good to have a common parent other than Object for all
>> user payloads, but it may be a marker interface as well.
>>
>> Thank you,
>>
>> Vlad
>>
>>
>> On 12/16/16 09:59, Bhupesh Chawda wrote:
>>
>>> Hi David,
>>>
>>> Actually, I was thinking of another API class called ControlTuple,
>>> different from the actual tuple class in buffer server or stram.
>>> This could serve as a way for the Buffer server publisher to understand
>>> that it is a control tuple and needs to be wrapped differently.
>>>
>>> ~ Bhupesh
>>>
>>>
>>>
>>> On Dec 16, 2016 22:28, "David Yan"  wrote:
>>>
>>>   // DefaultInputPort
>>>public void processControl(ControlTuple tuple)
>>>{
>>>  // Default Implementation to avoid need to implement it in all
>>> implementations
>>>}
>>> {code}
>>>
>>> {code}
>>>   // DefaultOutputPort
>>>public void emitControl(ControlTuple tuple)
>>>{
>>>}
>>>
>>> I think we don't need to expose the ControlTuple class to the operator
>>> developers because the window ID is just the current window ID when
these
>>> methods are called. How about making them just Object? We also need to
>>> provide the way for the user to specify custom serializer for the
control
>>> tuple.
>>>
>>> David
>>>
>>>
>>> On Thu, Dec 15, 2016 at 12:43 AM, Bhupesh Chawda <
bhup...@datatorrent.com
>>> >
>>> wrote:
>>>
>>> Hi All,

 Here are the initial interfaces:

 {code}
   // DefaultInputPort
public void processControl(ControlTuple tuple)
{
  // Default Implementation to avoid need to implement it in all
 implementations
}
 {code}

 {code}
   // DefaultOutputPort
public void emitControl(ControlTuple tuple)
{
}
 {code}

 We have an option to add these methods to the interfaces - InputPort
and
 OutputPort; But these would not be backward compatible and also not
 consistent with the current implementation of basic data tuple flow (as
 with process() and emit()).

 We also need to expose an interface / class for users to wrap their
 object
 and emit downstream. This should be part of API.

 {code}
 public class ControlTuple extends Tuple
 {
Object userObject;

public ControlTuple(long windowId, Object userObject)
{
  //
}
 }
 {code}

 The emitted tuples would traverse the same flow as with other control
 tuples. The plan is to intercept the control tuples in GenericNode and
 use
 the Reservior to emit the control tuples at the end of the window.

 GenericNode seems to be the best place to buffer incoming custom
control
 tuples without delivering them immediately to the operator port. Once
the
 end of the window is reached, we plan to use the reservoir sink to push
 them to the port. This is different behavior than any other control
tuple
 where we are changing the order of tuples in the stream. The custom

>>> control
>>>
 tuples will be buffered and not delivered to the ports until the end of

>>> the
>>>
 window.
 To accomplish this, we need to have a public method in
SweepableReservoir
 which allows to put a tuple back in the sink of the reservoir.

 ~ 

Re: [DISCUSS] Custom Control Tuples Design

[Tushar Gosavi]

We do not need to create an interface for data emitted through
emitControl or processed through processControl. Internally we could
wrap the user object in ControlTuple. you can add type parameter for
control tuple object on ports.

DefaultInputPort
D is the data type and C is the control tuple type for better error
catching at compile phase.


- Tushar.


On Sat, Dec 17, 2016 at 8:35 AM, Bhupesh Chawda  wrote:
> Agreed Vlad and David.
> I am just suggesting there should be a wrapper for the user object. It can
> be a marker interface and we can call it something else like
> "CustomControl".
>
> The user object will be wrapped in another class "ControlTuple" which
> traverses the BufferServer and will perhaps be extended from the
> packet/Tuple class. This class will not be exposed to the user.
>
> ~ Bhupesh
>
>
> On Sat, Dec 17, 2016 at 4:11 AM, Vlad Rozov  wrote:
>
>> I agree with David. Payload of the control tuple is in the userObject and
>> operators/ports don't need to be exposed to the implementation of the
>> ControlTuple class. With the proposed interface operators developers are
>> free to extend ControlTuple further and I don't think that such capability
>> needs to be provided. The wrapping in the ControlTuple class is necessary
>> and most likely ControlTuple needs to be extended from the buffer server
>> Tuple. It may be good to have a common parent other than Object for all
>> user payloads, but it may be a marker interface as well.
>>
>> Thank you,
>>
>> Vlad
>>
>>
>> On 12/16/16 09:59, Bhupesh Chawda wrote:
>>
>>> Hi David,
>>>
>>> Actually, I was thinking of another API class called ControlTuple,
>>> different from the actual tuple class in buffer server or stram.
>>> This could serve as a way for the Buffer server publisher to understand
>>> that it is a control tuple and needs to be wrapped differently.
>>>
>>> ~ Bhupesh
>>>
>>>
>>>
>>> On Dec 16, 2016 22:28, "David Yan"  wrote:
>>>
>>>   // DefaultInputPort
>>>public void processControl(ControlTuple tuple)
>>>{
>>>  // Default Implementation to avoid need to implement it in all
>>> implementations
>>>}
>>> {code}
>>>
>>> {code}
>>>   // DefaultOutputPort
>>>public void emitControl(ControlTuple tuple)
>>>{
>>>}
>>>
>>> I think we don't need to expose the ControlTuple class to the operator
>>> developers because the window ID is just the current window ID when these
>>> methods are called. How about making them just Object? We also need to
>>> provide the way for the user to specify custom serializer for the control
>>> tuple.
>>>
>>> David
>>>
>>>
>>> On Thu, Dec 15, 2016 at 12:43 AM, Bhupesh Chawda >> >
>>> wrote:
>>>
>>> Hi All,

 Here are the initial interfaces:

 {code}
   // DefaultInputPort
public void processControl(ControlTuple tuple)
{
  // Default Implementation to avoid need to implement it in all
 implementations
}
 {code}

 {code}
   // DefaultOutputPort
public void emitControl(ControlTuple tuple)
{
}
 {code}

 We have an option to add these methods to the interfaces - InputPort and
 OutputPort; But these would not be backward compatible and also not
 consistent with the current implementation of basic data tuple flow (as
 with process() and emit()).

 We also need to expose an interface / class for users to wrap their
 object
 and emit downstream. This should be part of API.

 {code}
 public class ControlTuple extends Tuple
 {
Object userObject;

public ControlTuple(long windowId, Object userObject)
{
  //
}
 }
 {code}

 The emitted tuples would traverse the same flow as with other control
 tuples. The plan is to intercept the control tuples in GenericNode and
 use
 the Reservior to emit the control tuples at the end of the window.

 GenericNode seems to be the best place to buffer incoming custom control
 tuples without delivering them immediately to the operator port. Once the
 end of the window is reached, we plan to use the reservoir sink to push
 them to the port. This is different behavior than any other control tuple
 where we are changing the order of tuples in the stream. The custom

>>> control
>>>
 tuples will be buffered and not delivered to the ports until the end of

>>> the
>>>
 window.
 To accomplish this, we need to have a public method in SweepableReservoir
 which allows to put a tuple back in the sink of the reservoir.

 ~ Bhupesh


>>

Re: [DISCUSS] Custom Control Tuples Design

[Bhupesh Chawda]

Agreed Vlad and David.
I am just suggesting there should be a wrapper for the user object. It can
be a marker interface and we can call it something else like
"CustomControl".

The user object will be wrapped in another class "ControlTuple" which
traverses the BufferServer and will perhaps be extended from the
packet/Tuple class. This class will not be exposed to the user.

~ Bhupesh


On Sat, Dec 17, 2016 at 4:11 AM, Vlad Rozov  wrote:

> I agree with David. Payload of the control tuple is in the userObject and
> operators/ports don't need to be exposed to the implementation of the
> ControlTuple class. With the proposed interface operators developers are
> free to extend ControlTuple further and I don't think that such capability
> needs to be provided. The wrapping in the ControlTuple class is necessary
> and most likely ControlTuple needs to be extended from the buffer server
> Tuple. It may be good to have a common parent other than Object for all
> user payloads, but it may be a marker interface as well.
>
> Thank you,
>
> Vlad
>
>
> On 12/16/16 09:59, Bhupesh Chawda wrote:
>
>> Hi David,
>>
>> Actually, I was thinking of another API class called ControlTuple,
>> different from the actual tuple class in buffer server or stram.
>> This could serve as a way for the Buffer server publisher to understand
>> that it is a control tuple and needs to be wrapped differently.
>>
>> ~ Bhupesh
>>
>>
>>
>> On Dec 16, 2016 22:28, "David Yan"  wrote:
>>
>>   // DefaultInputPort
>>public void processControl(ControlTuple tuple)
>>{
>>  // Default Implementation to avoid need to implement it in all
>> implementations
>>}
>> {code}
>>
>> {code}
>>   // DefaultOutputPort
>>public void emitControl(ControlTuple tuple)
>>{
>>}
>>
>> I think we don't need to expose the ControlTuple class to the operator
>> developers because the window ID is just the current window ID when these
>> methods are called. How about making them just Object? We also need to
>> provide the way for the user to specify custom serializer for the control
>> tuple.
>>
>> David
>>
>>
>> On Thu, Dec 15, 2016 at 12:43 AM, Bhupesh Chawda > >
>> wrote:
>>
>> Hi All,
>>>
>>> Here are the initial interfaces:
>>>
>>> {code}
>>>   // DefaultInputPort
>>>public void processControl(ControlTuple tuple)
>>>{
>>>  // Default Implementation to avoid need to implement it in all
>>> implementations
>>>}
>>> {code}
>>>
>>> {code}
>>>   // DefaultOutputPort
>>>public void emitControl(ControlTuple tuple)
>>>{
>>>}
>>> {code}
>>>
>>> We have an option to add these methods to the interfaces - InputPort and
>>> OutputPort; But these would not be backward compatible and also not
>>> consistent with the current implementation of basic data tuple flow (as
>>> with process() and emit()).
>>>
>>> We also need to expose an interface / class for users to wrap their
>>> object
>>> and emit downstream. This should be part of API.
>>>
>>> {code}
>>> public class ControlTuple extends Tuple
>>> {
>>>Object userObject;
>>>
>>>public ControlTuple(long windowId, Object userObject)
>>>{
>>>  //
>>>}
>>> }
>>> {code}
>>>
>>> The emitted tuples would traverse the same flow as with other control
>>> tuples. The plan is to intercept the control tuples in GenericNode and
>>> use
>>> the Reservior to emit the control tuples at the end of the window.
>>>
>>> GenericNode seems to be the best place to buffer incoming custom control
>>> tuples without delivering them immediately to the operator port. Once the
>>> end of the window is reached, we plan to use the reservoir sink to push
>>> them to the port. This is different behavior than any other control tuple
>>> where we are changing the order of tuples in the stream. The custom
>>>
>> control
>>
>>> tuples will be buffered and not delivered to the ports until the end of
>>>
>> the
>>
>>> window.
>>> To accomplish this, we need to have a public method in SweepableReservoir
>>> which allows to put a tuple back in the sink of the reservoir.
>>>
>>> ~ Bhupesh
>>>
>>>
>

Re: [DISCUSS] Custom Control Tuples Design

[Vlad Rozov]

I agree with David. Payload of the control tuple is in the userObject 
and operators/ports don't need to be exposed to the implementation of 
the ControlTuple class. With the proposed interface operators developers 
are free to extend ControlTuple further and I don't think that such 
capability needs to be provided. The wrapping in the ControlTuple class 
is necessary and most likely ControlTuple needs to be extended from the 
buffer server Tuple. It may be good to have a common parent other than 
Object for all user payloads, but it may be a marker interface as well.


Thank you,

Vlad

On 12/16/16 09:59, Bhupesh Chawda wrote:

Hi David,

Actually, I was thinking of another API class called ControlTuple,
different from the actual tuple class in buffer server or stram.
This could serve as a way for the Buffer server publisher to understand
that it is a control tuple and needs to be wrapped differently.

~ Bhupesh



On Dec 16, 2016 22:28, "David Yan"  wrote:

  // DefaultInputPort
   public void processControl(ControlTuple tuple)
   {
 // Default Implementation to avoid need to implement it in all
implementations
   }
{code}

{code}
  // DefaultOutputPort
   public void emitControl(ControlTuple tuple)
   {
   }

I think we don't need to expose the ControlTuple class to the operator
developers because the window ID is just the current window ID when these
methods are called. How about making them just Object? We also need to
provide the way for the user to specify custom serializer for the control
tuple.

David


On Thu, Dec 15, 2016 at 12:43 AM, Bhupesh Chawda 
wrote:


Hi All,

Here are the initial interfaces:

{code}
  // DefaultInputPort
   public void processControl(ControlTuple tuple)
   {
 // Default Implementation to avoid need to implement it in all
implementations
   }
{code}

{code}
  // DefaultOutputPort
   public void emitControl(ControlTuple tuple)
   {
   }
{code}

We have an option to add these methods to the interfaces - InputPort and
OutputPort; But these would not be backward compatible and also not
consistent with the current implementation of basic data tuple flow (as
with process() and emit()).

We also need to expose an interface / class for users to wrap their object
and emit downstream. This should be part of API.

{code}
public class ControlTuple extends Tuple
{
   Object userObject;

   public ControlTuple(long windowId, Object userObject)
   {
 //
   }
}
{code}

The emitted tuples would traverse the same flow as with other control
tuples. The plan is to intercept the control tuples in GenericNode and use
the Reservior to emit the control tuples at the end of the window.

GenericNode seems to be the best place to buffer incoming custom control
tuples without delivering them immediately to the operator port. Once the
end of the window is reached, we plan to use the reservoir sink to push
them to the port. This is different behavior than any other control tuple
where we are changing the order of tuples in the stream. The custom

control

tuples will be buffered and not delivered to the ports until the end of

the

window.
To accomplish this, we need to have a public method in SweepableReservoir
which allows to put a tuple back in the sink of the reservoir.

~ Bhupesh

Re: [DISCUSS] Custom Control Tuples Design

[Bhupesh Chawda]

Hi David,

Actually, I was thinking of another API class called ControlTuple,
different from the actual tuple class in buffer server or stram.
This could serve as a way for the Buffer server publisher to understand
that it is a control tuple and needs to be wrapped differently.

~ Bhupesh



On Dec 16, 2016 22:28, "David Yan"  wrote:

 // DefaultInputPort
  public void processControl(ControlTuple tuple)
  {
// Default Implementation to avoid need to implement it in all
implementations
  }
{code}

{code}
 // DefaultOutputPort
  public void emitControl(ControlTuple tuple)
  {
  }

I think we don't need to expose the ControlTuple class to the operator
developers because the window ID is just the current window ID when these
methods are called. How about making them just Object? We also need to
provide the way for the user to specify custom serializer for the control
tuple.

David


On Thu, Dec 15, 2016 at 12:43 AM, Bhupesh Chawda 
wrote:

> Hi All,
>
> Here are the initial interfaces:
>
> {code}
>  // DefaultInputPort
>   public void processControl(ControlTuple tuple)
>   {
> // Default Implementation to avoid need to implement it in all
> implementations
>   }
> {code}
>
> {code}
>  // DefaultOutputPort
>   public void emitControl(ControlTuple tuple)
>   {
>   }
> {code}
>
> We have an option to add these methods to the interfaces - InputPort and
> OutputPort; But these would not be backward compatible and also not
> consistent with the current implementation of basic data tuple flow (as
> with process() and emit()).
>
> We also need to expose an interface / class for users to wrap their object
> and emit downstream. This should be part of API.
>
> {code}
> public class ControlTuple extends Tuple
> {
>   Object userObject;
>
>   public ControlTuple(long windowId, Object userObject)
>   {
> //
>   }
> }
> {code}
>
> The emitted tuples would traverse the same flow as with other control
> tuples. The plan is to intercept the control tuples in GenericNode and use
> the Reservior to emit the control tuples at the end of the window.
>
> GenericNode seems to be the best place to buffer incoming custom control
> tuples without delivering them immediately to the operator port. Once the
> end of the window is reached, we plan to use the reservoir sink to push
> them to the port. This is different behavior than any other control tuple
> where we are changing the order of tuples in the stream. The custom
control
> tuples will be buffered and not delivered to the ports until the end of
the
> window.
> To accomplish this, we need to have a public method in SweepableReservoir
> which allows to put a tuple back in the sink of the reservoir.
>
> ~ Bhupesh
>

Re: [DISCUSS] Custom Control Tuples Design

[David Yan]

 // DefaultInputPort
  public void processControl(ControlTuple tuple)
  {
// Default Implementation to avoid need to implement it in all
implementations
  }
{code}

{code}
 // DefaultOutputPort
  public void emitControl(ControlTuple tuple)
  {
  }

I think we don't need to expose the ControlTuple class to the operator
developers because the window ID is just the current window ID when these
methods are called. How about making them just Object? We also need to
provide the way for the user to specify custom serializer for the control
tuple.

David


On Thu, Dec 15, 2016 at 12:43 AM, Bhupesh Chawda 
wrote:

> Hi All,
>
> Here are the initial interfaces:
>
> {code}
>  // DefaultInputPort
>   public void processControl(ControlTuple tuple)
>   {
> // Default Implementation to avoid need to implement it in all
> implementations
>   }
> {code}
>
> {code}
>  // DefaultOutputPort
>   public void emitControl(ControlTuple tuple)
>   {
>   }
> {code}
>
> We have an option to add these methods to the interfaces - InputPort and
> OutputPort; But these would not be backward compatible and also not
> consistent with the current implementation of basic data tuple flow (as
> with process() and emit()).
>
> We also need to expose an interface / class for users to wrap their object
> and emit downstream. This should be part of API.
>
> {code}
> public class ControlTuple extends Tuple
> {
>   Object userObject;
>
>   public ControlTuple(long windowId, Object userObject)
>   {
> //
>   }
> }
> {code}
>
> The emitted tuples would traverse the same flow as with other control
> tuples. The plan is to intercept the control tuples in GenericNode and use
> the Reservior to emit the control tuples at the end of the window.
>
> GenericNode seems to be the best place to buffer incoming custom control
> tuples without delivering them immediately to the operator port. Once the
> end of the window is reached, we plan to use the reservoir sink to push
> them to the port. This is different behavior than any other control tuple
> where we are changing the order of tuples in the stream. The custom control
> tuples will be buffered and not delivered to the ports until the end of the
> window.
> To accomplish this, we need to have a public method in SweepableReservoir
> which allows to put a tuple back in the sink of the reservoir.
>
> ~ Bhupesh
>

Re: [DISCUSS] Custom Control Tuples Design

[Bhupesh Chawda]

Yes, control tuples would be delivered in the same window in which they
were generated.
Only the tuples which are duplicated due to shuffling across multiple
stages would be deduplicated and then sent only once.

~ Bhupesh


On Dec 16, 2016 20:30, "Thomas Weise"  wrote:

Hi Bhupesh,

I don't see anything stateful here as control tuples are delivered at the
end of the streaming window in which they were generated?

Also, control tuples would need to be broadcast to all partitions, and
therefore also joined downstream by the engine? (In addition to the case
you describe where different partitions generate control tuples, which all
need to be delivered downstream).

Thanks,
Thomas



On Fri, Dec 16, 2016 at 5:15 AM, Bhupesh Chawda 
wrote:

> As I understand from the discussion on the other thread, we want custom
> control tuples to behave like existing control tuples similar to begin
> window and end window.
>
> However the fact that we are allowing the user to bundle a user object
> inside the control tuple differentiates it from the existing control
tuples
> and makes it a stateful tuple. This is what is delivered to the downstream
> operator during the call back.
>
> Perhaps we should add the following requirements for the custom control
> tuple behavior:
>
>1. All control tuples generated from upstream partitions must be
>delivered to the downstream operator. Since all control tuples have a
>different user object bundled inside, the engine should make sure that
> all
>of the control tuples are received by the down stream operator. However
> the
>callbacks would only be after all data tuples have been delivered to
the
>operator.
>2. The alternate behavior could be to behave similar to the existing
>control tuples (like begin window and end window) and consider the
> custom
>control tuple as stateless. Otherwise the question arises on which user
>object (from among all control tuples from upstream) is passed on to
the
>downstream operator.
>
> We can control the behavior via some attribute.
>
> Thoughts?
>
> ~ Bhupesh
>
>
>
>
> On Thu, Dec 15, 2016 at 2:13 PM, Bhupesh Chawda 
> wrote:
>
> > Hi All,
> >
> > Here are the initial interfaces:
> >
> > {code}
> >  // DefaultInputPort
> >   public void processControl(ControlTuple tuple)
> >   {
> > // Default Implementation to avoid need to implement it in all
> > implementations
> >   }
> > {code}
> >
> > {code}
> >  // DefaultOutputPort
> >   public void emitControl(ControlTuple tuple)
> >   {
> >   }
> > {code}
> >
> > We have an option to add these methods to the interfaces - InputPort and
> > OutputPort; But these would not be backward compatible and also not
> > consistent with the current implementation of basic data tuple flow (as
> > with process() and emit()).
> >
> > We also need to expose an interface / class for users to wrap their
> object
> > and emit downstream. This should be part of API.
> >
> > {code}
> > public class ControlTuple extends Tuple
> > {
> >   Object userObject;
> >
> >   public ControlTuple(long windowId, Object userObject)
> >   {
> > //
> >   }
> > }
> > {code}
> >
> > The emitted tuples would traverse the same flow as with other control
> > tuples. The plan is to intercept the control tuples in GenericNode and
> use
> > the Reservior to emit the control tuples at the end of the window.
> >
> > GenericNode seems to be the best place to buffer incoming custom control
> > tuples without delivering them immediately to the operator port. Once
the
> > end of the window is reached, we plan to use the reservoir sink to push
> > them to the port. This is different behavior than any other control
tuple
> > where we are changing the order of tuples in the stream. The custom
> control
> > tuples will be buffered and not delivered to the ports until the end of
> the
> > window.
> > To accomplish this, we need to have a public method in
SweepableReservoir
> > which allows to put a tuple back in the sink of the reservoir.
> >
> > ~ Bhupesh
> >
> >
>

Re: [DISCUSS] Custom Control Tuples Design

[Thomas Weise]

Hi Bhupesh,

I don't see anything stateful here as control tuples are delivered at the
end of the streaming window in which they were generated?

Also, control tuples would need to be broadcast to all partitions, and
therefore also joined downstream by the engine? (In addition to the case
you describe where different partitions generate control tuples, which all
need to be delivered downstream).

Thanks,
Thomas



On Fri, Dec 16, 2016 at 5:15 AM, Bhupesh Chawda 
wrote:

> As I understand from the discussion on the other thread, we want custom
> control tuples to behave like existing control tuples similar to begin
> window and end window.
>
> However the fact that we are allowing the user to bundle a user object
> inside the control tuple differentiates it from the existing control tuples
> and makes it a stateful tuple. This is what is delivered to the downstream
> operator during the call back.
>
> Perhaps we should add the following requirements for the custom control
> tuple behavior:
>
>1. All control tuples generated from upstream partitions must be
>delivered to the downstream operator. Since all control tuples have a
>different user object bundled inside, the engine should make sure that
> all
>of the control tuples are received by the down stream operator. However
> the
>callbacks would only be after all data tuples have been delivered to the
>operator.
>2. The alternate behavior could be to behave similar to the existing
>control tuples (like begin window and end window) and consider the
> custom
>control tuple as stateless. Otherwise the question arises on which user
>object (from among all control tuples from upstream) is passed on to the
>downstream operator.
>
> We can control the behavior via some attribute.
>
> Thoughts?
>
> ~ Bhupesh
>
>
>
>
> On Thu, Dec 15, 2016 at 2:13 PM, Bhupesh Chawda 
> wrote:
>
> > Hi All,
> >
> > Here are the initial interfaces:
> >
> > {code}
> >  // DefaultInputPort
> >   public void processControl(ControlTuple tuple)
> >   {
> > // Default Implementation to avoid need to implement it in all
> > implementations
> >   }
> > {code}
> >
> > {code}
> >  // DefaultOutputPort
> >   public void emitControl(ControlTuple tuple)
> >   {
> >   }
> > {code}
> >
> > We have an option to add these methods to the interfaces - InputPort and
> > OutputPort; But these would not be backward compatible and also not
> > consistent with the current implementation of basic data tuple flow (as
> > with process() and emit()).
> >
> > We also need to expose an interface / class for users to wrap their
> object
> > and emit downstream. This should be part of API.
> >
> > {code}
> > public class ControlTuple extends Tuple
> > {
> >   Object userObject;
> >
> >   public ControlTuple(long windowId, Object userObject)
> >   {
> > //
> >   }
> > }
> > {code}
> >
> > The emitted tuples would traverse the same flow as with other control
> > tuples. The plan is to intercept the control tuples in GenericNode and
> use
> > the Reservior to emit the control tuples at the end of the window.
> >
> > GenericNode seems to be the best place to buffer incoming custom control
> > tuples without delivering them immediately to the operator port. Once the
> > end of the window is reached, we plan to use the reservoir sink to push
> > them to the port. This is different behavior than any other control tuple
> > where we are changing the order of tuples in the stream. The custom
> control
> > tuples will be buffered and not delivered to the ports until the end of
> the
> > window.
> > To accomplish this, we need to have a public method in SweepableReservoir
> > which allows to put a tuple back in the sink of the reservoir.
> >
> > ~ Bhupesh
> >
> >
>

Re: [DISCUSS] Custom Control Tuples Design

[Bhupesh Chawda]

As I understand from the discussion on the other thread, we want custom
control tuples to behave like existing control tuples similar to begin
window and end window.

However the fact that we are allowing the user to bundle a user object
inside the control tuple differentiates it from the existing control tuples
and makes it a stateful tuple. This is what is delivered to the downstream
operator during the call back.

Perhaps we should add the following requirements for the custom control
tuple behavior:

   1. All control tuples generated from upstream partitions must be
   delivered to the downstream operator. Since all control tuples have a
   different user object bundled inside, the engine should make sure that all
   of the control tuples are received by the down stream operator. However the
   callbacks would only be after all data tuples have been delivered to the
   operator.
   2. The alternate behavior could be to behave similar to the existing
   control tuples (like begin window and end window) and consider the custom
   control tuple as stateless. Otherwise the question arises on which user
   object (from among all control tuples from upstream) is passed on to the
   downstream operator.

We can control the behavior via some attribute.

Thoughts?

~ Bhupesh




On Thu, Dec 15, 2016 at 2:13 PM, Bhupesh Chawda 
wrote:

> Hi All,
>
> Here are the initial interfaces:
>
> {code}
>  // DefaultInputPort
>   public void processControl(ControlTuple tuple)
>   {
> // Default Implementation to avoid need to implement it in all
> implementations
>   }
> {code}
>
> {code}
>  // DefaultOutputPort
>   public void emitControl(ControlTuple tuple)
>   {
>   }
> {code}
>
> We have an option to add these methods to the interfaces - InputPort and
> OutputPort; But these would not be backward compatible and also not
> consistent with the current implementation of basic data tuple flow (as
> with process() and emit()).
>
> We also need to expose an interface / class for users to wrap their object
> and emit downstream. This should be part of API.
>
> {code}
> public class ControlTuple extends Tuple
> {
>   Object userObject;
>
>   public ControlTuple(long windowId, Object userObject)
>   {
> //
>   }
> }
> {code}
>
> The emitted tuples would traverse the same flow as with other control
> tuples. The plan is to intercept the control tuples in GenericNode and use
> the Reservior to emit the control tuples at the end of the window.
>
> GenericNode seems to be the best place to buffer incoming custom control
> tuples without delivering them immediately to the operator port. Once the
> end of the window is reached, we plan to use the reservoir sink to push
> them to the port. This is different behavior than any other control tuple
> where we are changing the order of tuples in the stream. The custom control
> tuples will be buffered and not delivered to the ports until the end of the
> window.
> To accomplish this, we need to have a public method in SweepableReservoir
> which allows to put a tuple back in the sink of the reservoir.
>
> ~ Bhupesh
>
>

[DISCUSS] Custom Control Tuples Design

[Bhupesh Chawda]

Hi All,

Here are the initial interfaces:

{code}
 // DefaultInputPort
  public void processControl(ControlTuple tuple)
  {
// Default Implementation to avoid need to implement it in all
implementations
  }
{code}

{code}
 // DefaultOutputPort
  public void emitControl(ControlTuple tuple)
  {
  }
{code}

We have an option to add these methods to the interfaces - InputPort and
OutputPort; But these would not be backward compatible and also not
consistent with the current implementation of basic data tuple flow (as
with process() and emit()).

We also need to expose an interface / class for users to wrap their object
and emit downstream. This should be part of API.

{code}
public class ControlTuple extends Tuple
{
  Object userObject;

  public ControlTuple(long windowId, Object userObject)
  {
//
  }
}
{code}

The emitted tuples would traverse the same flow as with other control
tuples. The plan is to intercept the control tuples in GenericNode and use
the Reservior to emit the control tuples at the end of the window.

GenericNode seems to be the best place to buffer incoming custom control
tuples without delivering them immediately to the operator port. Once the
end of the window is reached, we plan to use the reservoir sink to push
them to the port. This is different behavior than any other control tuple
where we are changing the order of tuples in the stream. The custom control
tuples will be buffered and not delivered to the ports until the end of the
window.
To accomplish this, we need to have a public method in SweepableReservoir
which allows to put a tuple back in the sink of the reservoir.

~ Bhupesh